NOTE: Notice 3, dated 5 February 1996, changes the

METRIC
cover page of this standard for administrative reasons.
There are no other changes to this document.
MIL–STD–462D
11 JANUARY 1993
SUPERSEDING
MIL–STD–462
31 JULY 1967

DEPARTMENT OF DEFENSE
TEST METHOD STANDARD
FOR
MEASUREMENT OF
ELECTROMAGNETIC INTERFERENCE CHARACTERISTICS

AMSC N/A AREA EMCS

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

Supersedes cover page of MIL–STD–462D, Notice 2, dated 1 December 1995.

 MIL-STD-462D

FOREWORD

1. This military standard is approved for use by all

Departments and Agencies of the Department of Defense.

2. Recommended corrections, additions, or deletions should be

addressed to Aeronautical Systems Division (ENES), Wright-
Patterson Air Force Base, Ohio, 45433-6503.

3. This standard contains the general test methods necessary to

demonstrate compliance of subsystems and equipment to the
requirements of MIL-STD-461. An appendix has been introduced
which provides the rationale and background for each paragraph.

4. This standard is designated as revision "D" to coincide with

its companion document, MIL-STD-461. Revisions "A," "B," and "C"
of MIL-STD-462 were never issued.

5. Substantial changes have been made from previous editions.

Some test methods have been eliminated, others significantly
changed, and new ones added.

6. A joint committee consisting of representatives of the Army,

Air Force, Navy, and Industry prepared this document.

ii
 MIL-STD-462D

CONTENTS

PARAGRAPH PAGE

1. SCOPE . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Purpose . . . . . . . . . . . . . . . . . . . . . 1
1.2 Application . . . . . . . . . . . . . . . . . . . 1
1.3 Emission and susceptibility designations . . . . . 1

2. APPLICABLE DOCUMENTS . . . . . . . . . . . . . . . . 2
2.1 Government documents . . . . . . . . . . . . . . . 2
2.1.1 Specifications, standards, and handbooks . . . . . 2
2.1.2 Other Government documents, drawings, and
publications . . . . . . . . . . . . . . . . . . 2
2.2 Non-Government publications . . . . . . . . . . . 2

3. DEFINITIONS . . . . . . . . . . . . . . . . . . . . 5
3.1 General . . . . . . . . . . . . . . . . . . . . . 5
3.2 Acronyms used in this standard . . . . . . . . . . 5
3.3 Metric units . . . . . . . . . . . . . . . . . . . 5
3.4 Test setup boundary . . . . . . . . . . . . . . . 5

4. REQUIREMENTS . . . . . . . . . . . . . . . . . . . . 6
4.1 General . . . . . . . . . . . . . . . . . . . . . 6
4.1.1 Measurement tolerances . . . . . . . . . . . . . . 6
4.2 Shielded enclosures . . . . . . . . . . . . . . . 6
4.2.1 Radio Frequency (RF) absorber material . . . . . . 6
4.3 Other test sites . . . . . . . . . . . . . . . . . 7
4.4 Ambient electromagnetic level . . . . . . . . . . 7
4.5 Ground plane . . . . . . . . . . . . . . . . . . . 7
4.5.1 Metallic ground plane . . . . . . . . . . . . . . 7
4.5.2 Composite ground plane . . . . . . . . . . . . . . 8
4.6 Power source impedance . . . . . . . . . . . . . . 8
4.7 General test precautions . . . . . . . . . . . . . 8
4.7.1 Accessory equipment . . . . . . . . . . . . . . . 8
4.7.2 Excess personnel and equipment . . . . . . . . . . 8
4.7.3 Overload precautions . . . . . . . . . . . . . . . 8
4.7.4 RF hazards . . . . . . . . . . . . . . . . . . . . 9
4.7.5 Shock hazard . . . . . . . . . . . . . . . . . . . 9
4.7.6 Federal Communications Commission (FCC)
restrictions . . . . . . . . . . . . . . . . . . 9
4.8 EUT test configurations . . . . . . . . . . . . . 9
4.8.1 Bonding of EUT . . . . . . . . . . . . . . . . . . 9
4.8.2 Shock and vibration isolators . . . . . . . . . . 9
4.8.3 Wire grounds . . . . . . . . . . . . . . . . . . . 9
4.8.4 Orientation of EUTs . . . . . . . . . . . . . . . 10
4.8.5 Construction and arrangement of EUT cables . . . . 10
4.8.5.1 Interconnecting leads and cables . . . . . . . . . 10
4.8.5.2 Input power leads . . . . . . . . . . . . . . . . 10
4.8.6 Electrical and mechanical interfaces . . . . . . . 11

iii
 MIL-STD-462D

CONTENTS

PARAGRAPH PAGE

4.9 Operation of EUT . . . . . . . . . . . . . . . . . 11

4.9.1 Operating frequencies for tunable RF
equipment . . . . . . . . . . . . . . . . . . . 11
4.9.2 Operating frequencies for spread spectrum
equipment . . . . . . . . . . . . . . . . . . . 11
4.9.3 Susceptibility monitoring . . . . . . . . . . . . 12
4.10 Use of measurement equipment . . . . . . . . . . . 12
4.10.1 Detector . . . . . . . . . . . . . . . . . . . . . 12
4.10.2 Computer-controlled receivers . . . . . . . . . . 12
4.10.3 Emission testing . . . . . . . . . . . . . . . . . 12
4.10.3.1 Bandwidths . . . . . . . . . . . . . . . . . . . . 12
4.10.3.2 Emission identification . . . . . . . . . . . . . 13
4.10.3.3 Frequency scanning . . . . . . . . . . . . . . . . 13
4.10.3.4 Emission data presentation . . . . . . . . . . . . 13
4.10.4 Susceptibility testing . . . . . . . . . . . . . . 13
4.10.4.1 Frequency scanning . . . . . . . . . . . . . . . . 14
4.10.4.2 Modulation of susceptibility signals . . . . . . . 14
4.10.4.3 Thresholds of susceptibility . . . . . . . . . . . 14
4.11 Calibration of measuring equipment and
antennas . . . . . . . . . . . . . . . . . . . . 15
4.11.1 Measurement system test . . . . . . . . . . . . . 15
4.12 Antenna factors . . . . . . . . . . . . . . . . . 15

5. MEASUREMENT PROCEDURES . . . . . . . . . . . . . . . 16
CE101 CONDUCTED EMISSIONS, POWER LEADS, 30 Hz TO
10 kHz . . . . . . . . . . . . . . . . . . . . . 25
CE102 CONDUCTED EMISSIONS, POWER LEADS, 10 kHz TO
10 MHz . . . . . . . . . . . . . . . . . . . . . 31
CE106 CONDUCTED EMISSIONS, ANTENNA TERMINAL, 10 kHz
TO 40 GHz . . . . . . . . . . . . . . . . . . . 37
CS101 CONDUCTED SUSCEPTIBILITY, POWER LEADS, 30 Hz
TO 50 kHz . . . . . . . . . . . . . . . . . . . 45
CS103 CONDUCTED SUSCEPTIBILITY, ANTENNA PORT,
INTERMODULATION, 15 kHz to 10 GHz . . . . . . . 53
CS104 CONDUCTED SUSCEPTIBILITY, ANTENNA PORT,
REJECTION OF UNDESIRED SIGNALS, 30 kHz to
20 GHz . . . . . . . . . . . . . . . . . . . . . 55
CS105 CONDUCTED SUSCEPTIBILITY, ANTENNA PORT,
CROSS MODULATION, 30 kHz to 20 GHz . . . . . . . 57
CS109 CONDUCTED SUSCEPTIBILITY, STRUCTURE CURRENT,
60 Hz TO 100 kHz . . . . . . . . . . . . . . . . 59
CS114 CONDUCTED SUSCEPTIBILITY, BULK CABLE
INJECTION, 10 kHz TO 400 MHz . . . . . . . . . . 63
CS115 CONDUCTED SUSCEPTIBILITY, BULK CABLE
INJECTION, IMPULSE EXCITATION . . . . . . . . . 69

iv
 MIL-STD-462D

CONTENTS

TEST METHOD PAGE

CS116 CONDUCTED SUSCEPTIBILITY, DAMPED SINUSOIDAL

TRANSIENTS, CABLES AND POWER LEADS, 10 kHz
TO 100 MHz . . . . . . . . . . . . . . . . . . . 75
RE101 RADIATED EMISSIONS, MAGNETIC FIELD, 30 Hz TO
100 kHz . . . . . . . . . . . . . . . . . . . . 83
RE102 RADIATED EMISSIONS, ELECTRIC FIELD, 10 kHz TO
18 GHz . . . . . . . . . . . . . . . . . . . . . 89
RE103 RADIATED EMISSIONS, ANTENNA SPURIOUS AND
HARMONIC OUTPUTS, 10 kHz TO 40 GHz . . . . . . . 97
RS101 RADIATED SUSCEPTIBILITY, MAGNETIC FIELD,
30 Hz TO 100 kHz . . . . . . . . . . . . . . . . 103
RS103 RADIATED SUSCEPTIBILITY, ELECTRIC FIELD,
10 kHz TO 40 GHz . . . . . . . . . . . . . . . . 109
RS105 RADIATED SUSCEPTIBILITY, TRANSIENT
ELECTROMAGNETIC FIELD . . . . . . . . . . . . . 119

TABLE
I Absorption at normal incidence . . . . . . . . . . 7
II Bandwidth and measurement time . . . . . . . . . . 13
III Susceptibility scanning . . . . . . . . . . . . . 14
IV Index of measurement procedures . . . . . . . . . 17

FIGURE

1 RF absorber loading diagram . . . . . . . . . . . 18

2 General test setup . . . . . . . . . . . . . . . . 19
3 Test setup for non-conductive surface mounted EUT 20
4 Test setup for free standing EUT, multiple EUT,
shielded enclosure . . . . . . . . . . . . . . . 21
5 Test setup for free standing EUT . . . . . . . . . 22
6 LISN schematic . . . . . . . . . . . . . . . . . . 23
7 LISN impedance . . . . . . . . . . . . . . . . . . 24

APPENDIX

A MIL-STD-462D Application Guide . . . . . . . . . . . A-1

v/vi
 MIL-STD-462D

1. SCOPE

1.1 Purpose. This standard establishes general techniques

for use in the measurement and determination of the
electromagnetic emission and susceptibility characteristics of
electronic, electrical, and electromechanical equipment and
subsystems designed or procured for use by activities and
agencies of the Department of Defense.

1.2 Application. The testing techniques of this standard

are used to obtain data for determination of compliance with the
specified MIL-STD-461 requirements. The test methods contained
in this document shall be adapted by the testing activity for
each application. The adapted test methods shall be documented
in the Electromagnetic Interference Test Procedures (EMITP)
required by MIL-STD-461.

1.3 Emission and susceptibility designations. The test

methods contained in this standard are designated in accordance
with an alpha-numeric coding system. Each method is identified
by a two letter combination followed by a three digit number.
The number is for reference purposes only. The meaning of the
individual letters are as follows:

C = Conducted
R = Radiated
E = Emissions
S = Susceptibility

a. Conducted emissions tests are designated by "CE---."

b. Radiated emissions tests are designated by "RE---."
c. Conducted susceptibility tests are designated by "CS---."
d. Radiated susceptibility test are designated by "RS---."
e. "---" = numerical order of test from 101 to 199.

1
 MIL-STD-462D

2. APPLICABLE DOCUMENTS

2.1 Government documents.

2.1.1 Specifications, standards, and handbooks. The

following specifications, standards, and handbooks form a part of
this document to the extent specified herein. Unless otherwise
specified, the issues of these documents are those listed in the
issue of the Department of Defense Index of Specifications and
Standards (DODISS) and supplement thereto, cited in the
solicitation.

STANDARDS

MILITARY

MIL-STD-461 - Requirements for the Control

of Electromagnetic
Interference Emissions and
Susceptibility

MIL-STD-45662 - Calibration Systems

Requirements

(Copies of federal and military specifications, standards,

and handbooks are available from the Naval Publications and Forms
Center, ATTN: NPODS, 700 Robbins Avenue, Philadelphia, PA
19111-5093.)

2.1.2 Other Government documents, drawings, and

publications. The following other Government documents,
drawings, and publications form a part of this document to the
extent specified herein. Unless otherwise specified, the issues
are those cited in the solicitation.

DODISS - Department of Defense Index of

Specifications and Standards

(Copies of the DODISS are available on a yearly subscription

basis either from the Government Printing Office for hard copy,
or microfiche copies are available from the Director, Navy
Publications and Printing Service Office, 700 Robbins Avenue,
Philadelphia, PA 19111-5093.)

2.2 Non-Government publications. The following documents

form a part of this document to the extent specified herein.
Unless otherwise specified, the issues of the documents which are
DOD adopted are those listed in the issue of the DODISS cited in
the solicitation. Unless otherwise specified, the issues of

2
 MIL-STD-462D

documents not listed in the DODISS are the issues of the

documents cited in the solicitation.

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

ANSI/IEEE 268 - Metric Practice. (DOD adopted)

ANSI C63.2 - Standard for Instrumentation-

Electromagnetic Noise and Field
Strength, 10 kHz to 40 GHz -
Specifications

ANSI C63.4 - Standard for Electromagnetic

Compatibility - Radio-Noise
Emissions from Low Voltage
Electrical and Electronic
Equipment in the Range of 9 kHz to
40 GHz - Methods of Measurement.

ANSI C63.14 - Standard Dictionary for

Technologies of Electromagnetic
Compatibility (EMC),
Electromagnetic Pulse (EMP), and
Electrostatic Discharge (ESD).

ANSI C95.1 - Standard for Safety Levels with

Respect to Human Exposure to Radio
Frequency Electromagnetic Fields
(300 kHz - 100 GHz).

(Application for copies should be addressed to the IEEE

Service Center, 445 Hoes Lane, PO Box 1331, Piscataway, NJ
08855-1331.)

SOCIETY OF AUTOMOTIVE ENGINEERS (SAE)

ARP 958 - Electromagnetic Interference

Measurement Antennas; Standard
Calibration Requirements and
Methods

(Application for copies should be addressed to the Society

of Automotive Engineers, Inc., 400 Commonwealth Drive,
Warrendale, PA 15096.)

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM E 380 - Standard for Metric Practice. (DOD

adopted)

3
 MIL-STD-462D

(Application for copies should be addressed to the American

Society for Testing and Materials, 1916 Race Street,
Philadelphia, PA 19103-1187.)

4
 MIL-STD-462D

3. DEFINITIONS

3.1 General. The terms used in this standard are defined

in ANSI C63.14. In addition, the following definitions are
applicable for the purpose of this standard.

3.2 Acronyms used in this standard.

a. BIT - Built-in Test

b. EMI - Electromagnetic Interference

c. EMITP - Electromagnetic Interference Test Procedures

d. EMITR - Electromagnetic Interference Test Report

e. ERP - Effective Radiated Power

f. EUT - Equipment Under Test

g. LISN - Line Impedance Stabilization Network

h. RF - Radio Frequency

i. RMS - Root Mean Square

j. TEM - Transverse Electromagnetic

k. TPD - Terminal Protection Device

3.3 Metric units. Metric units are a system of basic

measures which are defined by the International System of Units
based on "Le System International d’Unites (SI)", of the
International Bureau of Weights and Measures. These units are
described in ASTM E 380 and ANSI/IEEE 268.

3.4 Test setup boundary. The test setup boundary includes

all enclosures of the Equipment Under Test (EUT) and the 2 meters
of exposed interconnecting leads (except for leads which are
shorter in the actual installation) and power leads required by
the general section of this standard.

5
 MIL-STD-462D

4. REQUIREMENTS

4.1 General. General requirements related to test methods,

test facilities, and equipment are as stated below. Any approved
exceptions or deviations from these general test requirements
shall be documented in the EMITP required by MIL-STD-461.

4.1.1 Measurement tolerances. Unless otherwise stated for

a particular measurement, the tolerance shall be as follows:

a. Distance: ±5%

b. Frequency: ±2%

c. Amplitude, measurement receiver: ±2 dB

d. Amplitude, measurement system (includes measurement

receivers, transducers, cables, and so forth): ±3 dB

e. Time (waveforms): ±5%

4.2 Shielded enclosures. To prevent interaction between

the EUT and the outside environment, shielded enclosures will
usually be required for testing. These enclosures prevent
external environment signals from contaminating emission
measurements and susceptibility test signals from interfering
with electrical and electronic items in the vicinity of the test
facility. Shielded enclosures must have adequate attenuation
such that the ambient requirements of paragraph 4.4 are
satisfied. The enclosures must be sufficiently large such that
the EUT arrangement requirements of paragraph 4.8 and antenna
positioning requirements described in the individual test methods
are satisfied.

4.2.1 Radio Frequency (RF) absorber material. RF absorber

material (carbon impregnated foam pyramids, ferrite tiles, and so
forth) shall be used when performing electric field radiated
emissions or radiated susceptibility testing inside a shielded
enclosure to reduce reflections of electromagnetic energy and to
improve accuracy and repeatability. The RF absorber shall be
placed above, behind, and on both sides of the EUT, and behind
the radiating or receiving antenna as shown in Figure 1. Minimum
performance of the material shall be as specified in Table I.
The manufacturer’s certification of their RF absorber material
(basic material only, not installed) is acceptable.

6
 MIL-STD-462D

TABLE I. Absorption at normal incidence.

Frequency Minimum absorption

80 MHz - 250 MHz 6 dB
above 250 MHz 10 dB

4.3 Other test sites. If other test sites are used, the
ambient requirements of paragraph 4.4 shall be met.

4.4 Ambient electromagnetic level. During testing, the

ambient electromagnetic level measured with the EUT de-energized
and all auxiliary equipment turned on shall be at least 6 dB
below the allowable specified limits when the tests are performed
in a shielded enclosure. Ambient conducted levels on power leads
shall be measured with the leads disconnected from the EUT and
connected to a resistive load which draws the same rated current
as the EUT. When tests are performed in a shielded enclosure and
the EUT is in compliance with MIL-STD-461 limits, the ambient
profile need not be recorded in the Electromagnetic Interference
Test Report (EMITR). When measurements are made outside a
shielded enclosure, the tests shall be performed during times and
conditions when the ambient is at its lowest level. The ambient
shall be recorded in the EMITR required by MIL-STD-461 and shall
not compromise the test results.

4.5 Ground plane. The EUT shall be installed on a ground

plane that simulates the actual installation. If the actual
installation is unknown or multiple installations are expected,
then a metallic ground plane shall be used. Unless otherwise
specified below, ground planes shall be 2.25 square meters or
larger in area with the smaller side no less than 76 centimeters.
When a ground plane is not present in the EUT installation, the
EUT shall be placed on a non-conductive surface.

4.5.1 Metallic ground plane. When the EUT is installed on

a metallic ground plane, the ground plane shall have a surface
resistance no greater than 0.1 milliohms per square. The DC
resistance between metallic ground planes and the shielded
enclosure shall be 2.5 milliohms or less. The metallic ground
planes shown in Figures 2 through 5 shall be electrically bonded
to the floor or wall of the basic shielded room structure at
least once every 1 meter. The metallic bond straps shall be
solid and maintain a five-to-one ratio or less in length to
width. Metallic ground planes used outside a shielded enclosure
shall be at least 2 meters by 2 meters and extend at least
0.5 meter beyond the test setup boundary.

7
 MIL-STD-462D

4.5.2 Composite ground plane. When the EUT is installed on

a conductive composite ground plane, the surface resistivity of
the typical installation shall be used. Composite ground planes
shall be electrically bonded to the enclosure with means suitable
to the material.

4.6 Power source impedance. The impedance of power sources

providing input power to the EUT shall be controlled by Line
Impedance Stabilization Networks (LISNs) for all measurement
procedures of this document unless otherwise stated in a
particular test method. The LISNs shall be located at the power
source end of the exposed length of power leads specified in
paragraph 4.8.5.2. The LISN circuit shall be in accordance with
the schematic shown in Figure 6. The LISN impedance
characteristics shall be in accordance with Figure 7. The LISN
impedance shall be measured at least annually under the following
conditions:

a. The impedance shall be measured between the power output

lead on the load side of the LISN and the metal
enclosure of the LISN.

b. The signal output port of the LISN shall be terminated

in fifty ohms.

c. The power input terminal on the power source side of the

LISN shall be unterminated.

The impedance measurement results shall be provided in the EMITR

required by MIL-STD-461.

4.7 General test precautions.

4.7.1 Accessory equipment. Accessory equipment used in
conjunction with measurement receivers shall not degrade
measurement integrity.

4.7.2 Excess personnel and equipment. The test area shall

be kept free of unnecessary personnel, equipment, cable racks,
and desks. Only the equipment essential to the test being
performed shall be in the test area or enclosure. Only personnel
actively involved in the test shall be permitted in the
enclosure.

4.7.3 Overload precautions. Measurement receivers and

transducers are subject to overload, especially receivers without
preselectors and active transducers. Periodic checks shall be
performed to assure that an overload condition does not exist.

8
 MIL-STD-462D

Instrumentation changes shall be implemented to correct any

overload condition.

4.7.4 RF hazards. Some tests in this standard will result

in electromagnetic fields which are potentially dangerous to
personnel. The permissible exposure levels in ANSI C95.1 shall
not be exceeded in areas where personnel are present. Safety
procedures and devices shall be used to prevent accidental
exposure of personnel to RF hazards.

4.7.5 Shock hazard. Some of the tests require potentially

hazardous voltages to be present. Extreme caution must be taken
by all personnel to assure that all safety precautions are
observed.

4.7.6 Federal Communications Commission (FCC) restrictions.

Some of the tests require high level signals to be generated that
could interfere with normal FCC approved frequency assignments.
All such testing should be conducted in a shielded enclosure.
Some open site testing may be feasible if prior FCC coordination
is obtained.

4.8 EUT test configurations. The EUT shall be configured

as shown in the general test setups of Figures 1 through 5 as
applicable. These setups shall be maintained during all testing
unless other direction is given for a particular test method.

4.8.1 Bonding of EUT. Only the provisions included in the

design of the EUT shall be used to bond units such as equipment
case and mounting bases together, or to the ground plane. When
bonding straps are required to complete the test setup, they
shall be identical to those specified in the installation
drawings.

4.8.2 Shock and vibration isolators. EUTs shall be secured

to mounting bases having shock or vibration isolators if such
mounting bases are used in the installation. The bonding straps
furnished with the mounting base shall be connected to the ground
plane. When mounting bases do not have bonding straps, bonding
straps shall not be used in the test setup.

4.8.3 Wire grounds. When external terminals, connector

pins, or equipment grounding conductors in power cables are
available for ground connections and are used in the actual
installation, they shall be connected to the ground plane after a
2 meter exposed length (see 4.8.5). Shorter lengths shall be
used if they are specified in the installation instructions.

9
 MIL-STD-462D

4.8.4 Orientation of EUTs. EUTs shall be oriented such

that surfaces which produce maximum radiated emissions and
respond most readily to radiated signals face the measurement
antennas. Bench mounted EUTs shall be located 10 ±2 centimeters
from the front edge of the ground plane subject to allowances for
providing adequate room for cable arrangement as specified below.

4.8.5 Construction and arrangement of EUT cables.

Electrical cable assemblies shall simulate actual installation
and usage. Shielded cables or shielded leads (including power
leads and wire grounds) within cables shall be used only if they
have been specified in installation drawings. Cables shall be
checked against installation requirements to verify proper
construction techniques such as use of twisted pairs, shielding,
and shield terminations. Details on the cable construction used
for testing shall be included in the EMITP.

4.8.5.1 Interconnecting leads and cables. Individual leads

shall be grouped into cables in the same manner as in the actual
installation. Total interconnecting cable lengths in the setup
shall be the same as in the actual platform installation. If a
cable is longer than 10 meters, at least 10 meters shall be
included. When cable lengths are not specified for the
installation, cables shall be sufficiently long to satisfy the
conditions specified below. At least 2 meters (except for cables
which are shorter in the actual installation) of each
interconnecting cable shall be run parallel to the front boundary
of the setup. Remaining cable lengths shall be routed to the
back of the setup and shall be placed in a zig-zagged
arrangement. When the setup includes more than one cable,
individual cables shall be separated by 2 centimeters measured
from their outer circumference. For bench top setups using
ground planes, the cable closest to the front boundary shall be
placed 10 centimeters from the front edge of the ground plane.
All cables shall be supported 5 centimeters above the ground
plane.

4.8.5.2 Input power leads. Two meters of input power leads

(including returns) shall be routed parallel to the front edge of
the setup in the same manner as the interconnecting leads. The
power leads shall be connected to the LISNs (see 4.6). Power
leads that are part of an interconnecting cable shall be
separated out at the EUT connector and routed to the LISNs.
After the 2 meter exposed length, the power leads shall be
terminated at the LISNs in as short a distance as possible. The
total length of power lead from the EUT electrical connector to
the LISNs shall not exceed 2.5 meters. All power leads shall be
supported 5 centimeters above the ground plane. If the power

10
 MIL-STD-462D

leads are twisted in the actual installation, they shall be

twisted up to the LISNs.

4.8.6 Electrical and mechanical interfaces. All electrical

input and output interfaces shall be terminated with either the
actual equipment from the platform installation or loads which
simulate the electrical properties (impedance, grounding,
balance, and so forth) present in the actual installation.
Signal inputs shall be applied to all applicable electrical
interfaces to exercise EUT circuitry. EUTs with mechanical
outputs shall be suitably loaded. When variable electrical or
mechanical loading is present in the actual installation, testing
shall be performed under expected worst case conditions. When
active electrical loading (such as a test set) is used,
precautions shall be taken to insure the active load meets the
ambient requirements of paragraph 4.4 when connected to the
setup, and that the active load does not respond to
susceptibility signals. Antenna ports on the EUT shall be
terminated with shielded, matched loads.

4.9 Operation of EUT. During emission measurements, the

EUT shall be placed in an operating mode which produces maximum
emissions. During susceptibility testing, the EUT shall be
placed in its most susceptible operating mode. For EUTs with
several available modes (including software controlled
operational modes), a sufficient number of modes shall be tested
for emissions and susceptibility such that all circuitry is
evaluated.

4.9.1 Operating frequencies for tunable RF equipment.

Measurements shall be performed with the EUT tuned to not less
than three frequencies within each tuning band, tuning unit, or
range of fixed channels, consisting of one mid-band frequency and
a frequency within ±5 percent from each end of each band or range
of channels.

4.9.2 Operating frequencies for spread spectrum equipment.

Operating frequency requirements for two major types of spread
spectrum equipment shall be as follows:

a. Frequency hopping. Measurements shall be performed with

the EUT utilizing a hop set which contains 30% of the
total possible frequencies. The hop set shall be
divided equally into three segments at the low, mid, and
high end of the EUT’s operational frequency range.

b. Direct sequence. Measurements shall be performed with

the EUT processing data at the highest possible data
transfer rate.

11
 MIL-STD-462D

4.9.3 Susceptibility monitoring. The EUT shall be

monitored during susceptibility testing for indications of
degradation or malfunction. This monitoring is normally
accomplished through the use of built-in-test (BIT), visual
displays, aural outputs, and other measurements of signal outputs
and interfaces. Monitoring of EUT performance through
installation of special circuitry in the EUT is permissible;
however, these modifications shall not influence test results.

4.10 Use of measurement equipment. Measurement equipment

shall be as specified in the individual test methods of this
standard. Any frequency selective measurement receiver may be
used for performing the testing described in this standard
provided that the receiver characteristics (that is, sensitivity,
selection of bandwidths, detector functions, dynamic range, and
frequency of operation) meet the constraints specified in this
standard and are sufficient to demonstrate compliance with the
applicable limits of MIL-STD-461. Typical instrumentation
characteristics may be found in ANSI C63.2.

4.10.1 Detector. A peak detector shall be used for all

frequency domain emission and susceptibility measurements. This
device detects the peak value of the modulation envelope in the
receiver bandpass. Measurement receivers are calibrated in terms
of an equivalent Root Mean Square (RMS) value of a sine wave that
produces the same peak value. When other measurement devices such
as oscilloscopes, non-selective voltmeters, or broadband field
strength sensors are used for susceptibility testing, correction
factors shall be applied for test signals to adjust the reading
to equivalent RMS values under the peak of the modulation
envelope.

4.10.2 Computer-controlled receivers. A description of the

operations being directed by software for computer-controlled
receivers shall be included in the EMITP required by MIL-STD-461.
Verification techniques used to demonstrate proper performance of
the software shall also be included.

4.10.3 Emission testing.

4.10.3.1 Bandwidths. The measurement receiver bandwidths

listed in Table II shall be used for emission testing. These
bandwidths are specified at the 6 dB down points for the overall
selectivity curve of the receivers. Video filtering shall not be
used to bandwidth limit the receiver response. If a controlled
video bandwidth is available on the measurement receiver, it
shall be set to its greatest value. Larger bandwidths may be
used; however, they may result in higher measured emission

12
 MIL-STD-462D

levels. NO BANDWIDTH CORRECTION FACTORS SHALL BE APPLIED TO TEST

DATA DUE TO THE USE OF LARGER BANDWIDTHS.

TABLE II. Bandwidth and measurement time.

Frequency Range 6 dB Dwell Minimum Measurement Time

Bandwidth Time Analog Measurement
Receiver
30 Hz - 1 kHz 10 Hz 0.15 sec 0.015 sec/Hz
1 kHz - 10 kHz 100 Hz 0.015 sec 0.15 sec/kHz
10 kHz - 250 kHz 1 kHz 0.015 sec 0.015 sec/kHz
250 kHz - 30 MHz 10 kHz 0.015 sec 1.5 sec/MHz
30 MHz - 1 GHz 100 kHz 0.015 sec 0.15 sec/MHz
Above 1 GHz 1 MHz 0.015 sec 15 sec/GHz

4.10.3.2 Emission identification. All emissions regardless

of characteristics shall be measured with the measurement
receiver bandwidths specified in Table II and compared against
the limits in MIL-STD-461. Identification of emissions with
regard to narrowband or broadband categorization is not
applicable.

4.10.3.3 Frequency scanning. For emission measurements,

the entire frequency range for each applicable test shall be
scanned. Minimum measurement time for analog measurement
receivers during emission testing shall be as specified in
Table II. Synthesized measurement receivers shall step in one-
half bandwidth increments or less, and the measurement dwell time
shall be as specified in Table II.

4.10.3.4 Emission data presentation. Amplitude versus

frequency profiles of emission data shall be automatically and
continuously plotted. The applicable limit shall be displayed on
the plot. Manually gathered data is not acceptable except for
plot verification. The plotted data for emissions measurements
shall provide a minimum frequency resolution of 1% or twice the
measurement receiver bandwidth, whichever is less stringent, and
minimum amplitude resolution of 1 dB. The above resolution
requirements shall be maintained in the reported results of the
EMITR.

4.10.4 Susceptibility testing.

13
 MIL-STD-462D

4.10.4.1 Frequency scanning. For susceptibilty

measurements, the entire frequency range for each applicable test
shall be scanned. For swept frequency susceptibility testing,
frequency scan rates and frequency step sizes of signal sources
shall not exceed the values listed in Table III. The rates and
step sizes are specified in terms of a multiplier of the tuned
frequency (fo) of the signal source. Analog scans refer to
signal sources which are continuously tuned. Stepped scans refer
to signal sources which are sequentially tuned to discrete
frequencies. Stepped scans shall dwell at each tuned frequency
for a minimum of 1 second. Scan rates and step sizes shall be
decreased when necessary to permit observation of a response.

TABLE III. Susceptibility scanning.

Analog Scans Stepped Scans

Frequency Range Maximum Scan Rates Maximum Step Size

30 Hz - 1 MHz 0.02 fo/sec 0.01 fo

1 MHz - 30 MHz 0.01 fo/sec 0.005 fo

30 MHz - 1 GHz 0.005 fo/sec 0.0025 fo

1 GHz - 8 GHz 0.002 fo/sec 0.001 fo

8 GHz - 40 GHz 0.001 fo/sec 0.0005 fo

4.10.4.2 Modulation of susceptibility signals.

Susceptibility test signals above 10 kHz shall be pulse modulated
at a 1 kHz rate with a 50% duty cycle unless otherwise specified
in an individual test method of this standard.

4.10.4.3 Thresholds of susceptibility. When susceptibility

indications are noted in EUT operation, a threshold level shall
be determined where the susceptible condition is no longer
present. Thresholds of susceptibility shall be determined as
follows:

a. When a susceptibility condition is detected, reduce the

interference signal until the EUT recovers.

b. Reduce the interference signal by an additional 6 dB.

c. Gradually increase the interference signal until the

susceptibility condition reoccurs. The resulting level
is the threshold of susceptibility.

14
 MIL-STD-462D

d. Record this level, frequency range of occurrence,

frequency and level of greatest susceptibility, and
other test parameters, as applicable.

4.11 Calibration of measuring equipment and antennas. Test

equipment and accessories required for measurement in accordance
with this standard shall be calibrated under an approved program
in accordance with MIL-STD-45662. In particular, measurement
antennas, current probes, field sensors, and other devices used
in the measurement loop shall be calibrated at least every
2 years unless otherwise specified by the procuring activity, or
when damage is apparent. Antenna factors and current probe
transfer impedances shall be determined on an individual basis
for each device.

4.11.1 Measurement system test. At the start of each

emission test, the complete test system (including measurement
receivers, cables, attenuators, couplers, and so forth) shall be
verified by injecting a known signal, as stated in the individual
test method, while monitoring system output for the proper
indication.

4.12 Antenna factors. Factors for electric field test

antennas shall be determined in accordance with SAE ARP-958.

15
 MIL-STD-462D

5. MEASUREMENT PROCEDURES

This section contains the measurement procedures to be used

in determining compliance with the emission and susceptibility
requirements of MIL-STD-461. The test procedures are applicable
for the entire specified frequency range; however, certain
equipment or classes of equipment may not require testing
throughout the complete measurement frequency range. These
modifications are specified in MIL-STD-461. Table IV is an index
of measurement procedures by method number and title.

16
 MIL-STD-462D

TABLE IV. Index of measurement procedures.

Requirement Description
CE101 Conducted Emissions, Power Leads, 30 Hz to
10 kHz
CE102 Conducted Emissions, Power Leads, 10 kHz to
10 MHz
CE106 Conducted Emissions, Antenna Terminal, 10 kHz to
40 GHz
CS101 Conducted Susceptibility, Power Leads, 30 Hz to
50 kHz
CS103 Conducted Susceptibility, Antenna Port,
Intermodulation, 15 kHz to 10 GHz
CS104 Conducted Susceptibility, Antenna Port,
Rejection of Undesired Signals, 30 Hz to 20 GHz
CS105 Conducted Susceptibility, Antenna Port,
Cross-Modulation, 30 Hz to 20 GHz
CS109 Conducted Susceptibility, Structure Current,
60 Hz to 100 kHz
CS114 Conducted Susceptibility, Bulk Cable Injection,
10 kHz to 400 MHz
CS115 Conducted Susceptibility, Bulk Cable Injection,
Impulse Excitation
CS116 Conducted Susceptibility, Damped Sinusoidal
Transients, Cables and Power Leads, 10 kHz to
100 MHz
RE101 Radiated Emissions, Magnetic Field, 30 Hz to
100 kHz
RE102 Radiated Emissions, Electric Field, 10 kHz to
18 GHz
RE103 Radiated Emissions, Antenna Spurious and
Harmonic Outputs, 10 kHz to 40 GHz
RS101 Radiated Susceptibility, Magnetic Field, 30 Hz
to 100 kHz
RS103 Radiated Susceptibility, Electric Field, 10 kHz
to 40 GHz
RS105 Radiated Susceptibility, Transient
Electromagnetic Field

17
 MIL-STD-462D

RF absorber placed above,

behind and on both sides of
test setup boundary, from
ceiling to ground plane

≥30 cm
TEST SETUP
BOUNDARY
≥30 cm

≥50 cm

≥30 cm
Test
Antenna

≥30 cm

RF absorber placed
behind test antenna,
from ceiling to floor

FIGURE 1. RF absorber loading diagram.

18
 Interconnecting Cable

FIGURE 2.
Power
Source

5 cm Above 2 cm

19
Ground Plane LISN

EUT 10 cm
MIL-STD-462D

2m
80-90 cm

General test setup.

 FIGURE 3.
Interconnecting Cable

Power
Cable

GROUND
PLANE

20
LISN
2 cm
EUT
MIL-STD-462D

10 cm NON-CONDUCTIVE
TABLE

2m 80-90 cm

Test setup for non-conductive surface mounted EUT.

 Access Panel

Ground

shielded enclosure.
EUT EUT EUT Plane

21
MIL-STD-462D

LISN LISN LISN

5 cm Above Floor
2 m Power Cable Ground Plane Interconnecting
Cables

FIGURE 4. Test setup for free standing EUT, multiple EUT,

 MIL-STD-462D

e
Abov
5 cm nd Plane
Grou

Po
LISN

we
r In
EUT
2m

PLANE
O U N D
GR
Min
50 um
cm
im

FIGURE 5. Test setup for free standing EUT.

22
 MIL-STD-462D

50 µH
To
Power To EUT
Source
8 µF 0.25 µF

To 50Ω Termination
Or 50Ω Input Of
Measurement
Receiver
5Ω 1kΩ

Signal Output
Port

FIGURE 6. LISN schematic.

23
 MIL-STD-462D

Tolerance ±20%
100
Impedance (Ohms)

10

1
10k 100k 1M 10M 100M
Frequency (Hz)

FIGURE 7. LISN impedance.

24
 MIL-STD-462D

METHOD CE101

CONDUCTED EMISSIONS, POWER LEADS, 30 Hz TO 10 kHz

1. Purpose. This test method is used to verify that

electromagnetic emissions from the EUT do not exceed the
specified requirements for power input leads including returns.

2. Test Equipment. The test equipment shall be as follows:

a. Measurement receivers

b. Current probes

c. Signal generator

d. Data recording device

e. Oscilloscope

f. Resistor (R)

g. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 2 through 5 and paragraph 4.8 of the
general section of this standard. The LISN may be
removed or replaced with an alternative stabilization
device when approved by the procuring activity.

b. Calibration. Configure the test setup for the

measurement system check as shown in Figure CE101-1.

c. EUT testing.

(1) Configure the test setup for compliance testing of

the EUT as shown in Figure CE101-2.

(2) Position the current probe 5 cm from the LISN.

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the measurement equipment and allow a sufficient

time for stabilization.

METHOD CE101
25 11 January 1993
 MIL-STD-462D

b. Calibration. Evaluate the overall measurement system

from the current probe to the data output device.

(1) Apply a calibrated signal level, which is 6 dB below

the MIL-STD-461 limit at 1 kHz, 3 kHz, and 10 kHz, to
the current probe.

(2) Verify the current level, using the oscilloscope and

load resistor; also, verify that the current waveform
is sinusoidal.

(3) Scan the measurement receiver for each frequency in

the same manner as a normal data scan. Verify that
the data recording device indicates a level within
±3 dB of the injected level.

(4) If readings are obtained which deviate by more than

±3 dB, locate the source of the error and correct the
deficiency prior to proceeding with the testing.

c. EUT testing. Determine the conducted emissions from the

EUT input power leads, including returns.

(1) Turn on the EUT and allow sufficient time for

stabilization.

(2) Select an appropriate lead for testing and clamp the

current probe into position.

(3) Scan the measurement receiver over the applicable

frequency range, using the bandwidths and minimum
measurement times specified in the general section of
this standard.

(4) Repeat 4c(3) for each power lead.

5. Data Presentation. Data presentation shall be as follows:

a. Continuously and automatically plot amplitude versus

frequency profiles on X-Y axis outputs. Manually
gathered data is not acceptable except for plot
verification.

b. Display the applicable limit on each plot.

c. Provide a minimum frequency resolution of 1% or twice the

measurement receiver bandwidth, whichever is less

METHOD CE101
11 January 1993 26
 MIL-STD-462D

stringent, and a minimum amplitude resolution of 1 dB for

each plot.

d. Provide plots for both the measurement and system check

portions of the procedure.

METHOD CE101
27 11 January 1993
 MIL-STD-462D

Signal
Generator

Oscilloscope R

Current Probe

Data Recorder Measurement

Receiver

FIGURE CE101-1. Measurement system check setup.

METHOD CE101
11 January 1993 28
 MIL-STD-462D

5 cm

Power
Lead LISN EUT

Current Probe

Measurement
Receiver

Data Recorder

FIGURE CE101-2. Measurement setup.

METHOD CE101
29/30 11 January 1993
 MIL-STD-462D

METHOD CE102

CONDUCTED EMISSIONS, POWER LEADS, 10 kHz TO 10 MHz

1. Purpose. This test method is used to verify that

electromagnetic emissions from the EUT do not exceed the
specified requirements for power input leads, including returns.

2. Test Equipment. The test equipment shall be as follows:

a. Measurement receiver

b. Data recording device

c. Signal generator

d. Attenuator, 20 dB

e. Oscilloscope

f. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 2 through 5 and paragraph 4.8 of the
general section of this standard.

b. Calibration.

(1) Configure the test setup for the measurement system

check as shown in Figure CE102-1. Ensure that the
EUT power source is turned off.

(2) Connect the measurement receiver to the 20 dB

attenuator on the signal output port of the LISN.

c. EUT testing.

(1) Configure the test setup for compliance testing of

the EUT as shown in Figure CE102-2.

(2) Connect the measurement receiver to the 20 dB

attenuator on the signal output port of the LISN.

4. Test Procedures. The test procedures shall be as follows:

METHOD CE102
31 11 January 1993
 MIL-STD-462D

a. Calibration. Perform the measurement system check using

the measurement system check setup of Figure CE102-1.

(1) Turn on the measurement equipment and allow a

sufficient time for stabilization.

(2) Apply a calibrated signal level, which is 6 dB below

the MIL-STD-461 limit at 10 kHz, 100 kHz, 2 MHz and
10 MHz to the power output terminal of the LISN.
Also, verify that the voltage waveform is sinusoidal.

(3) Scan the measurement receiver for each frequency in

the same manner as a normal data scan. Verify that
the measurement receiver indicates a level within
±3 dB of the injected level. Correction factors
shall be applied for the 20 dB attenuator and the
voltage drop due to the LISN 0.25 microfarad coupling
capacitor.

(4) If readings are obtained which deviate by more than

±3 dB, locate the source of the error and correct the
deficiency prior to proceeding with the testing.

b. EUT testing. Perform emission data scans using the

measurement setup of Figure CE102-2.

(1) Turn on the EUT and allow a sufficient time for

stabilization.

(2) Select an appropriate lead for testing.

(3) Scan the measurement receiver over the applicable

frequency range, using the bandwidths and minimum
measurement times in the general section of this
standard.

(4) Repeat 4b(2) and 4b(3) for each power lead.

5. Data Presentation. Data presentation shall be as follows:

a. Continuously and automatically plot amplitude versus

frequency profiles on X-Y axis outputs. Manually
gathered data is not acceptable except for plot
verification.

b. Display the applicable limit on each plot.

METHOD CE102
11 January 1993 32
 MIL-STD-462D

c. Provide a minimum frequency resolution of 1% or twice the

measurement receiver bandwidth, whichever is less
stringent, and a minimum amplitude resolution of 1 dB for
each plot.

d. Provide plots for both the measurement system check and

measurement portions of the procedure.

METHOD CE102
33 11 January 1993
 MIL-STD-462D

Coaxial
"T" Connector

Power Signal
Input Generator
(Off)
LISN

Oscilloscope

Signal Total Length < 2 m

Output
Port

Measurement
Attenuator Receiver

Data
Recording
Device

FIGURE CE102-1. Measurement system check setup.

METHOD CE102
11 January 1993 34
 MIL-STD-462D

Power
Lead
Power
Input
LISN EUT

Signal
Output
Port

Measurement
Attenuator Receiver

Data
Recording
Device

FIGURE CE102-2. Measurement setup.

METHOD CE102
35/36 11 January 1993
 MIL-STD-462D

METHOD CE106

CONDUCTED EMISSIONS, ANTENNA TERMINAL, 10 kHz TO 40 GHz

1. Purpose. This test method is used to verify that conducted

emissions appearing at the antenna terminal of the EUT do not
exceed specified requirements.

2. Test Equipment. The test equipment shall be as follows:

a. Measurement receiver

b. Attenuators

c. Rejection networks

d. Directional couplers

e. Dummy loads

f. Signal generators

g. Data recording device

3. Test Setup. It is not necessary to maintain the basic test

setup for the EUT as shown and described in figures 2 through 5
and paragraph 4.8 of the general section of this standard. The
test setup shall be as follows:

a. Calibration. Configure the test setup for the signal

generator path shown in Figures CE106-1 through CE106-3
as applicable. The choice of figure CE106-1 or CE106-2
is dependent upon the power handling capability of the
measuring equipment.

b. EUT Testing. Configure the test setup for the EUT path
shown in Figures CE106-1 through CE106-3 as applicable.
The choice of figure CE106-1 or CE106-2 is dependent upon
the power handling capability of the measuring equipment.

4. Test Procedures.

4.1 Transmitters (Transmit Mode). The test procedure shall be

as follows:

a. Turn on the measurement equipment and allow a sufficient

time for stabilization.

METHOD CE106
37 11 January 1993
 MIL-STD-462D

b. Calibration.

(1) Apply a known calibrated signal level from the signal

generator through the system check path at a mid-band
fundamental frequency (fo) in accordance with the
general section of this standard.

(2) Scan the measurement receiver in the same manner as a

normal data scan. Verify the measurement receiver
detects a level within ±3 dB of the expected signal.

(3) If readings are obtained which deviate by more than

±3 dB, locate the source of the error and correct the
deficiency prior to proceeding with the test.

(4) Repeat 4.1b(1) through 4.1b(3) at the end points of

the frequency range of test.

c. EUT Testing.

(1) Turn on the EUT and allow sufficient time for

stabilization.

(2) Tune the EUT to the desired test frequency and use
the measurement path to complete the rest of this
procedure.

(3) Tune the test equipment to the measurement frequency

(fo) of the EUT and adjust for maximum indication.
(4) Apply the appropriate modulation for the EUT as
indicated in the equipment specification.

(5) Record the power level of the fundamental frequency

(fo) and the measurement receiver bandwidth.

(6) Insert the fundamental frequency rejection network,

when applicable.

(7) Scan the frequency range of interest and record the

level of all harmonics and spurious emissions. Add
all correction factors for cable loss, attenuators
and rejection networks. Maintain the same
measurement receiver bandwidth used to measure the
power level of the fundamental frequency (fo) in
4.1c(5).

METHOD CE106
11 January 1993 38
 MIL-STD-462D

(8) Verify spurious outputs are from the EUT and not
spurious responses of the measurement system.

(9) Repeat 4.1c(2) through 4.1c(8) for other fo of the

EUT.

(10) Determine measurement path losses at each spurious

frequency as follows:

(a) Replace the EUT with a signal generator.

(b) Retain all couplers and rejection networks in the

measurement path.

(c) Determine the losses through the measurement

path. The value of attenuators may be reduced to
facilitate the end-to-end check with a low level
signal generator.

4.2 Transmitters (Stand-by Mode) and Receivers. The test

procedure shall be as follows:

a. Turn on the measurement equipment and allow a sufficient

time for stabilization.

b. Calibration.

(1) Apply a calibrated signal level, which 6 dB below the

MIL-STD-461 limit, from the signal generator through
the system check path at a midpoint test frequency in
accordance with the general section of this standard.

(2) Scan the measurement receiver in the same manner as a

normal data scan. Verify the measurement receiver
detects a level within ±3 dB of the injected signal.

(3) If readings are obtained which deviate by more than

±3 dB, locate the source of the error and correct the
deficiency prior to proceeding with the test.

(4) Repeat 4.2b(1) through 4.2b(3) at the end points of

the frequency range of test.

c. EUT Testing.

(1) Turn on the EUT and allow sufficient time for

stabilization.

METHOD CE106
39 11 January 1993
 MIL-STD-462D

(2) Tune the EUT to the desired test frequency and use
the measurement path to complete the rest of this
procedure.

(3) Scan the measurement receiver over the applicable

frequency range, using the bandwidths and minimum
measurement times of the general section of this
standard.

(4) Repeat 4.2c(2) and 4.2c(3) for other frequencies as

required by the general section of this standard.

5. Data Presentation.

5.1 Transmitters (Transmit Mode). The data presentation shall

be as follows:

a. Provide graphical or tabular data showing fo and

frequencies of all harmonics and spurious emissions
measured, power level of the fundamental and all
harmonics and spurious emissions, dB down level, and all
correction factors including cable loss, attenuator pads,
and insertion loss of rejection networks.

b. The relative dB down level is determined by subtracting

the level in 4.1c(7) from that obtained in 4.1c(5).

5.2 Transmitters (Stand-by Mode) and Receivers. The data

presentation shall be as follows:

a. Continuously and automatically plot amplitude versus

frequency profiles for each tuned frequency. Manually
gathered data is not acceptable except for plot
verification.

b. Display the applicable limit on each plot.

c. Provide a minimum frequency resolution of 1% or twice the

measurement receiver bandwidth, whichever is less
stringent, and a minimum amplitude resolution of 1 dB for
each plot.

d. Provide plots for both the measurement and system check

portions of the procedure.

METHOD CE106
11 January 1993 40
 MIL-STD-462D

EUT

Path for
Signal Measurement
Generator

Path for Attenuator

System Check

Rejection
If Required Network

Measurement
Receiver

FIGURE CE106-1. Setup for low power transmitter.

METHOD CE106
41 11 January 1993
 MIL-STD-462D

Path for Path for

System Check Measurement
EUT

Signal
Generator

Dummy Load
or
Shielded Coupler
Antenna

Attenuator

Rejection
If Required Network

Measurement
Receiver

FIGURE CE106-2. Setup for high power transmitter.

METHOD CE106
11 January 1993 42
 MIL-STD-462D

EUT

Path for
Signal Measurement
Generator

Path for Attenuator

System Check

Measurement
Receiver

Data
Recording
Device

FIGURE CE106-3. Setup for transmitters (stand-by mode)

and receivers.

METHOD CE106
43/44 11 January 1993
 MIL-STD-462D

METHOD CS101

CONDUCTED SUSCEPTIBILITY, POWER LEADS, 30 Hz TO 50 kHz

1. Purpose. This test method is used to verify the ability of

the EUT to withstand signals coupled onto input power leads.

2. Test Equipment. The test equipment shall be as follows:

a. Signal generator

b. Power amplifier

c. Oscilloscope

d. Coupling transformer

e. Capacitor, 10 µF

f. Isolation transformer

g. Resistor, 0.5 ohm

h. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 2 through 5 and paragraph 4.8 of the
general section of this standard.

b. Calibration. Configure the test equipment in accordance

with Figure CS101-1. Set up the oscilloscope to monitor
the voltage across the 0.5 ohm resistor.

c. EUT testing.

(1) For DC or single phase AC power, configure the test

equipment as shown in Figure CS101-2.

(2) For three phase delta power, configure the test setup
as shown in Figure CS101-3.

(3) For three phase wye power (four power leads),

configure the test setup as shown in Figure CS101-4.

4. Test Procedures. The test procedures shall be as follows:

METHOD CS101
45 11 January 1993
 MIL-STD-462D

a. Turn on the measurement equipment and allow sufficient

time for stabilization.

b. Calibration.

(1) Set the signal generator to the lowest test

frequency.

(2) Increase the applied signal until the oscilloscope

indicates the voltage level corresponding to the
maximum required power level specified in
MIL-STD-461. Verify the output waveform is
sinusoidal.

(3) Record the setting of the signal source.

(4) Scan the required frequency range for testing and

record the signal source setting needed to maintain
the required power level.

c. EUT Testing.

(1) Turn on the EUT and allow sufficient time for

stabilization. CAUTION: Exercise care when
performing this test since the "safety ground" of the
oscilloscope is disconnected and a shock hazard may
be present.

(2) Set the signal generator to the lowest test

frequency. Increase the signal level until the
required voltage or power level is reached on the
power lead. (Note: Voltage is limited to the level
calibrated in 4b(2).)

(3) While maintaining at least the required signal level,

scan through the required frequency range at a rate
no greater than specified in Table III of the general
section of this standard.

(4) Susceptibility evaluation.

(a) Monitor the EUT for degradation of performance.

(b) If susceptibility is noted, determine the level

at which the undesirable response is no longer
present and verify that it is above the
MIL-STD-461 requirement.

METHOD CS101
11 January 1993 46
 MIL-STD-462D

(5) Repeat 4c(2) through 4c(4) for each power lead, as

required. For three phase delta power, the
measurements shall be made according to the following
table:

Coupling Transformer Voltage Measurement

in Line From
A A to B
B B to C
C C to A

For three phase wye power (four leads) the

measurements shall be made according to the following
table:

Coupling Transformer Voltage Measurement

in Line From
A A to neutral
B B to neutral
C C to neutral

5. Data Presentation. Data presentation shall be as follows:

a. Provide graphical or tabular data showing the frequencies

and amplitudes at which the test was conducted for each
lead.

b. Provide data on any susceptibility thresholds and the

associated frequencies which were determined for each
power lead.

c. Provide indications of compliance with the MIL-STD-461

requirements for the susceptibility evaluation specified
in 4c for each lead.

METHOD CS101
47 11 January 1993
 MIL-STD-462D

Signal
Generator

Power
Amplifier

Coupling
Transformer

Oscilloscope 0.5 Ω

FIGURE CS101-1. Calibration.

METHOD CS101
11 January 1993 48
 Stimulation Isolation Signal
and

FIGURE CS101-2.
Transformer Generator
Monitoring
Equipment

Power
Oscilloscope Amplifier

49
Power
MIL-STD-462D

Lead Coupling LISN

Transformer High
Return
EUT 10 µF
Power
Inputs

Signal injection, DC or single phase AC.

METHOD CS101
11 January 1993
METHOD CS101
Stimulation

11 January 1993
Isolation Signal
and Transformer Generator
Monitoring
Equipment

FIGURE CS101-3.
Power
Oscilloscope Amplifier

50
Power
MIL-STD-462D

Lead Coupling LISN

Transformer A
10 µF
B
EUT 10 µF 10 µF
C
Power
Inputs

Signal injection, 3-phase delta.

 Stimulation Isolation Signal
and Transformer Generator
Monitoring
Equipment

FIGURE CS101-4.
Power
Oscilloscope Amplifier

Power

51/52
Lead Coupling LISN
MIL-STD-462D

Transformer A
10 µF
B
EUT 10 µF
C
10 µF
Neutral
Power
Inputs

Signal injection, 3-phase wye.

METHOD CS101
11 January 1993
 MIL-STD-462D

METHOD CS103

CONDUCTED SUSCEPTIBILITY, ANTENNA PORT, INTERMODULATION,

15 kHz TO 10 GHz

1. Purpose. This test method is to determine the presence of

intermodulation products that may be caused by undesired signals
at the EUT antenna input terminals.

2. Test Requirements. The required test equipment, test setup,

test procedures, and data presentation shall be determined in
accordance with the guidance provided in the appendix of this
standard. The test requirements shall be described in the EMITP
required by MIL-STD-461.

METHOD CS103
53/54 11 January 1993
 MIL-STD-462D

METHOD CS104

CONDUCTED SUSCEPTIBILITY, ANTENNA PORT, REJECTION OF

UNDESIRED SIGNALS, 30 Hz TO 20 GHz

1. Purpose. This test method is to determine the presence of

spurious responses that may be caused by undesired signals at the
EUT antenna input terminals.

2. Test Requirements. The required test equipment, test setup,

test procedures, and data presentation shall be determined in
accordance with the guidance provided in the appendix of this
standard. The test requirements shall be described in the EMITP
required by MIL-STD-461.

METHOD CS104
55/56 11 January 1993
 MIL-STD-462D

METHOD CS105

CONDUCTED SUSCEPTIBILITY, ANTENNA PORT, CROSS-MODULATION,

30 Hz TO 20 GHz

1. Purpose. This test method is to determine the presence of

cross-modulation products that may be caused by undesired signals
at the EUT antenna terminals.

2. Test Requirements. The required test equipment, test setup,

test procedures, and data presentation shall be determined in
accordance with the guidance provided in the appendix of this
standard. The test requirements shall be described in the EMITP
required by MIL-STD-461.

METHOD CS105
57/58 11 January 1993
 MIL-STD-462D

METHOD CS109

CONDUCTED SUSCEPTIBILITY, STRUCTURE CURRENT, 60 Hz TO 100 kHz

1. Purpose. This test method is used to verify the ability of

the EUT to withstand structure currents.

2. Test Equipment. The test equipment shall be as follows:

a. Signal generator

b. Oscilloscope or voltmeter

c. Resistor, 0.5 ohm

d. Isolation transformers

3. Test Setup. The test setup shall be as follows:

a. It is not necessary to maintain the basic test setup for

the EUT as shown and described in figures 2 through 5 and
paragraph 4.8 of the general section of this standard.

b. Calibration. No special calibration is required.

c. EUT testing. CAUTION: Exercise care when setting up and

performing this test since the input power safety ground
leads are disconnected.

(1) As shown in Figure CS109-1, configure the EUT and the

test equipment (including the test signal source, the
test current measurement equipment, and the equipment
required for operating the EUT or measuring
performance degradation) to establish a single-point
ground for the test setup.

(a) Using isolation transformers, isolate all AC

power sources. For DC power, isolation
transformers are not applicable.

(b) Disconnect the safety ground leads of all input

power cables.

(c) Place the EUT and the test equipment on non-

conductive surfaces.

METHOD CS109
59 11 January 1993
 MIL-STD-462D

(2) The test points for injected currents shall be at

diagonal extremes across all surfaces of the EUT.

(3) Connect the signal generator and resistor to a

selected set of test points.

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the EUT and measurement equipment and allow

sufficient time for stabilization.

b. Set the signal generator to the lowest required

frequency. Adjust the signal generator to the required
level. Monitor the current by measuring the voltage
developed across the resistor.

c. Scan the signal generator over the required frequency

range in accordance with the general section of this
standard while maintaining the current level as specified
in the applicable limit. Monitor the EUT for
susceptibility.

d. If susceptibility is noted, determine the level at which

the undesirable response is no longer present and verify
that it is above the MIL-STD-461 requirement.

e. Repeat 4b through 4d for each diagonal set of test points

on each surface of the EUT to be tested.

5. Data Presentation. Data presentation shall be as follows:

a. Provide a table showing the mode of operation,

susceptible frequency, current threshold level, current
limit level, and susceptible test points.

METHOD CS109
11 January 1993 60
 MIL-STD-462D

AC DC
Power Power
Input Input

Isolation
Transformer

Single-
Point
Ground EUT

Oscilloscope
Isolation or
Transformer 0.5 Ω
Voltmeter

Isolation Signal
Transformer Generator

FIGURE CS109-1. Test Configuration.

METHOD CS109
61/62 11 January 1993
 MIL-STD-462D

METHOD CS114

CONDUCTED SUSCEPTIBILITY, BULK CABLE INJECTION, 10 kHz TO 400 MHz

1. Purpose. This test method is used to verify the ability of

the EUT to withstand RF signals coupled onto EUT associated
cabling.

2. Test Equipment. The test equipment shall be as follows:

a. Measurement receivers

b. Current injection probes

c. Current probes

d. Calibration fixture: coaxial transmission line with 50

ohm characteristic impedance, coaxial connections on both
ends, and space for an injection probe around the center
conductor.

e. Directional couplers

f. Signal generators

g. Plotter

h. Attenuators, 50 ohm

i. Coaxial loads, 50 ohm

j. Power amplifiers

k. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 2 through 5 and paragraph 4.8 of the
general section of this standard.

b. Calibration. Configure the test equipment in accordance

with Figure CS114-1 for calibrating injection probes.

(1) Place the injection probe around the center conductor

of the calibration fixture.

METHOD CS114
63 11 January 1993
 MIL-STD-462D

(2) Terminate one end of the calibration fixture with a

50 ohm load and terminate the other end with an
attenuator connected to measurement receiver A.

c. EUT Testing. Configure the test equipment as shown in

Figure CS114-2 for testing of the EUT.

(1) Place the injection and monitor probes around a cable

bundle interfacing with an EUT connector.

(2) Locate the monitor probe 5 cm from the connector. If

the overall length of the connector and backshell
exceeds 5 cm, position the monitor probe as close to
the connector’s backshell as possible.

(3) Position the injection probe 5 cm from the monitor

probe.

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the measurement equipment and allow sufficient

time for stabilization.

b. Calibration. Perform the following procedures using the

calibration setup.

(1) Set the signal generator to 10 kHz, unmodulated.

(2) Increase the applied signal until measurement

receiver A indicates the current level specified in
MIL-STD-461 is flowing in the center conductor of the
calibration fixture.

(3) Record the "forward power" to the injection probe

indicated on measurement receiver B.

(4) Scan the frequency band from 10 kHz to 400 MHz and
record the forward power needed to maintain the
required current amplitude.

c. EUT Testing. Perform the following procedures on each

cable bundle interfacing with each electrical connector
on the EUT including complete power cables (high sides
and returns). Also perform the procedures on power
cables with the power returns excluded from the cable
bundle.

METHOD CS114
11 January 1993 64
 MIL-STD-462D

(1) Turn on the EUT and allow sufficient time for

stabilization.

(2) Loop circuit impedance characterization.

(a) Set the signal generator to 10 kHz, unmodulated.

(b) Apply a power level of approximately 1 mW to the

injection probe and record both the power level
indicated by measurement receiver B and the
induced current level indicated by measurement
receiver A.

(c) Scan the frequency range from 10 kHz to 400 MHz

and record the applied power level and induced
current level.

(d) Normalize the measurement results to amperes for

1 watt of applied power.

(3) Susceptibility evaluation.

(a) Set the signal generator to 10 kHz with 1 kHz

pulse wave modulation, 50% duty cycle.

(b) Apply the forward power level determined under

4b(4) to the injection probe while monitoring the
induced current.

(c) Scan the required frequency range in accordance

with the general section of this standard while
maintaining the forward power level at the
calibration level determined under 4b(4), or the
maximum current level in MIL-STD-461, whichever
is less stringent.

(d) Monitor the EUT for degradation of performance

during testing.

(e) Whenever susceptibility is noted, determine the

level at which the undesirable response is no
longer present and verify that it is above the
MIL-STD-461 requirement.

(f) For EUTs with redundant cabling for safety

critical reasons such as multiple data buses, use
simultaneous multi-cable injection techniques.

METHOD CS114
65 11 January 1993
 MIL-STD-462D

5. Data Presentation. Data presentation shall be as follows:

a. Provide amplitude versus frequency plots for the forward

power levels required to obtain the calibration level as
determined in 4b.

b. Provide amplitude versus frequency plots for the amperes

for 1 watt of applied power for each EUT connector
interface as determined in 4c(2).

c. Provide tables showing scanned frequency ranges and

statements of compliance with the MIL-STD-461 requirement
for the susceptibility evaluation of 4c(3) for each
interface connector. Provide any susceptibility
thresholds which were determined, along with their
associated frequencies.

METHOD CS114
11 January 1993 66
 MIL-STD-462D

Signal
Generator

Coaxial Load Amplifier

Injection
Probe

Directional
Coupler

Calibration
Fixture
Attenuator

Measurement Measurement
Receiver Receiver
A B

Plotter

FIGURE CS114-1. Calibration setup.

METHOD CS114
67 11 January 1993
 MIL-STD-462D

Power
Input

LISN

Injection
Probe
5 cm
Monitor
Probe
5 cm

EUT Plotter

5 cm Measurement
Monitor Receiver
Probe A
5 cm
Injection
Probe Directional
Coupler Amplifier

Interconnecting
Cables
Measurement
Receiver Signal
Actual or Simulated B Generator
Loads and Signals

FIGURE CS114-2. Bulk cable injection and loop circuit

impedance evaluations.

METHOD CS114
11 January 1993 68
 MIL-STD-462D

METHOD CS115

CONDUCTED SUSCEPTIBILITY, BULK CABLE INJECTION,

IMPULSE EXCITATION

1. Purpose. This test method is used to verify the ability of

the EUT to withstand impulse signals coupled onto EUT associated
cabling.

2. Test Equipment. The test equipment shall be as follows:

a. Pulse generator, 50 ohm, charged line

b. Current injection probe

c. Drive cable, 50 ohm, 2 meters, 0.5 dB or less insertion

loss at 500 MHz

d. Current probe

e. Calibration fixture: coaxial transmission line with 50

ohm characteristic impedance, coaxial connections on both
ends, and space for an injection probe around the center
conductor.

f. Oscilloscope, 50 ohm input impedance

g. Attenuators, 50 ohm

h. Coaxial loads, 50 ohm

i. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 2 through 5 and paragraph 4.8 of the
general section of this standard.

b. Calibration. Configure the test equipment in accordance

with Figure CS115-1 for calibrating the injection probe.

(1) Place the injection probe around the center conductor

of the calibration fixture.

(2) Terminate one end of the calibration fixture with a

coaxial load and terminate the other end with an

METHOD CS115
69 11 January 1993
 MIL-STD-462D

attenuator connected to an oscilloscope with 50 ohm

input impedance.

c. EUT Testing. Configure the test equipment as shown in

Figure CS115-2 for testing of the EUT.

(1) Place the injection and monitor probes around a cable

bundle interfacing with an EUT connector.

(2) Locate the monitor probe 5 cm from the connector. If

the overall length of the connector and backshell
exceeds 5 cm, position the monitor probe as close to
the connector’s backshell as possible.

(3) Position the injection probe 5 cm from the monitor

probe.

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the measurement equipment and allow sufficient

time for stabilization.

b. Calibration. Perform the following procedures using the

calibration setup.

(1) Adjust the pulse generator source for the risetime,

pulse width, and pulse repetition rate requirements
specified in MIL-STD-461.

(2) Increase the signal applied to the calibration

fixture until the oscilloscope indicates that the
current level specified in MIL-STD-461 is flowing in
the center conductor of the calibration fixture.

(3) Verify that the rise time, fall time, and pulse width
portions of the waveform have the correct durations
and that the correct repetition rate is present. The
precise pulse shape will not be reproduced due to the
inductive coupling mechanism.

(4) Record the pulse generator amplitude setting.

c. EUT Testing.

(1) Turn on the EUT and allow sufficient time for

stabilization.

(2) Susceptibility evaluation.

METHOD CS115
11 January 1993 70
 MIL-STD-462D

(a) Adjust the pulse generator, as a minimum, for the

amplitude setting determined in 4b(4).

(b) Apply the test signal at the pulse repetition

rate and for the duration specified in
MIL-STD-461.

(c) Monitor the EUT for degradation of performance

during testing.

(d) Whenever susceptibility is noted, determine the

level at which the undesirable response is no
longer present and verify that it is above the
MIL-STD-461 requirement.

(e) Record the peak current induced in the cable as

indicated on the oscilloscope.

(f) Repeat 4c(2)(a) through 4c(2)(e) on each cable

bundle interfacing with each electrical connector
on the EUT. For power cables, perform 4c(2)(a)
through 4c(2)(e) on complete power cables (high
sides and returns) and on the power cables with
the power returns excluded from the cable bundle.

5. Data Presentation. Data presentation shall be as follows:

a. Provide tables showing statements of compliance with the

MIL-STD-461 requirement for the susceptibility evaluation
of 4c(2) and the induced current level for each interface
connector.

b. Provide any susceptibility thresholds which were

determined.

c. Provide oscilloscope photographs of injected waveforms

with test data.

METHOD CS115
71 11 January 1993
 MIL-STD-462D

Coaxial Load

Drive
Injection Cable
Probe

Pulse
Generator

Calibration
Fixture
Attenuator

Oscilloscope
(50 Ω Input)

FIGURE CS115-1. Calibration setup.

METHOD CS115
11 January 1993 72
 MIL-STD-462D

Power
Input

LISN

Injection
Probe
5 cm
Monitor
Probe
5 cm

EUT

5 cm
Oscilloscope
Monitor (50 Ω Input)
Probe
5 cm
Injection
Probe Pulse
Generator
Interconnecting
Cables
Drive Cable

Actual or Simulated
Loads and Signals

FIGURE CS115-2. Bulk cable injection.

METHOD CS115
73/74 11 January 1993
 MIL-STD-462D

METHOD CS116

CONDUCTED SUSCEPTIBILITY, DAMPED SINUSOIDAL TRANSIENTS,

CABLES AND POWER LEADS, 10 kHz TO 100 MHz

1. Purpose. This test method is used to verify the ability of

the EUT to withstand damped sinusoidal transients coupled onto
EUT associated cables and power leads.

2. Test Equipment. The test equipment shall be as follows:

a. Damped sinusoid transient generator, ≤ 100 ohm output

impedance

b. Current injection probe

c. Oscilloscope, 50 ohm input impedance

d. Calibration fixture: Coaxial transmission line with 50

ohm characteristic impedance, coaxial connections on both
ends, and space for an injection probe around the center
conductor

e. Current probes

f. Waveform recording device

g. Attenuators

h. Measurement receivers

i. Power amplifiers

j. Coaxial loads

k. Signal generators

l. Directional couplers

m. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 2 through 5 and paragraph 4.8 of the
general section of this standard.

METHOD CS116
75 11 January 1993
 MIL-STD-462D

b. Calibration. Configure the test equipment in accordance

with Figure CS116-1 for verification of the waveform.

c. EUT Testing:

(1) Loop Circuit Impedance Characterization.

(a) Configure the test equipment in accordance with

Figure CS116-2.

(b) Place the injection and monitor probes around a

cable bundle interfacing with an EUT connector.

(c) Locate the monitor probe 5 cm from the connector.

If the overall length of the connector and
backshell exceeds 5 cm, position the monitor
probe as close to the connector’s backshell as
possible.

(d) Position the injection probe 5 cm from the

monitor probe.

(2) Susceptibility Evaluation.

(a) Configure the test equipment as shown in Figure

CS116-3.

(b) Place the injection and monitor probes around a

cable bundle interfacing an EUT connector.

(c) Locate the monitor probe 5 cm from the connector.

If the overall length of the connector and
backshell exceeds 5 cm, position the monitor
probe as close to the connector’s backshell as
possible.

(d) Position the injection probe 5 cm from the

monitor probe.

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the measurement equipment and allow sufficient

time for stabilization.

b. Calibration. Perform the following procedures using the

calibration setup for waveform verification.

METHOD CS116
11 January 1993 76
 MIL-STD-462D

(1) Set the frequency of the damped sine generator at

10 kHz.

(2) Adjust the amplitude of the signal from the damped

sine generator to the level required in MIL-STD-461.

(3) Record the damped sine generator settings.

(4) Verify that the waveform complies with the

requirements of MIL-STD-461.

(5) Repeat 4b(2) through 4b(4) for each frequency

specified in MIL-STD-461 and those identified in
4c(2).

c. EUT Testing. Perform the following procedures, using the

EUT test setup on each cable bundle interfacing with each
connector on the EUT including complete power cables.
Also perform tests on each individual power lead.

(1) Turn on the EUT and allow sufficient time for

stabilization.

(2) Loop Circuit Impedance Characterization.

(a) Set the signal generator to 10 kHz, unmodulated.

(b) Apply a power level of approximately 1 mW to the

injection probe and record both the power level
indicated by measurement receiver B and the
induced current level indicated by measurement
receiver A.

(c) Scan the frequency range from 10 kHz to 100 MHz

and record the applied power and induced current
level.

(d) Adjust the measurement results to amperes for

1 watt of applied power.

(e) Identify the resonance frequencies where the

maximum and minimum impedances occur.

(3) Susceptibility evaluation.

(a) Turn on the EUT and measurement equipment to

allow sufficient time for stabilization.

METHOD CS116
77 11 January 1993
 MIL-STD-462D

(b) Set the damped sine generator to a test

frequency.

(c) Apply the test signals to each cable or power

lead of the EUT sequentially. Slowly increase
the damped sinewave generator output level to
provide the specified current, but not exceeding
the precalibrated generator output level. Record
the peak current obtained.

(d) Monitor the EUT for degradation of performance.

(e) If susceptibility is noted, determine the level

at which the undesirable response is no longer
present and verify that it is above the specified
requirements.

(f) Repeat 4c(3)(b) through 4c(3)(e) for each test

frequency as specified in MIL-STD-461 and
resonance frequencies as determined in 4c(2).
Repeat testing in 4c(3) for the power-off
condition.

5. Data Presentation. Data presentation shall be as follows:

a. Provide a list of the frequencies and amplitudes at which

the test was conducted for each cable and lead.

b. Provide amplitude versus frequency plots for the amperes

for 1 watt of applied power for each EUT connector
interface as determined in 4c(2)(d).

c. Provide data on any susceptibility thresholds and the

associated frequencies which were determined for each
connector and power lead.

d. Provide indications of compliance with the MIL-STD-461

requirements for the susceptibility evaluation specified
in 4c for each interface connector.

e. Provide oscilloscope photographs of injected waveforms

with test data.

METHOD CS116
11 January 1993 78
 MIL-STD-462D

Coaxial Load

Injection
Probe

Damped Sinusoid
Transient Generator

Calibration
Fixture
Attenuator

Storage
Oscilloscope

FIGURE CS116-1. Typical test setup for calibration of

test waveform.

METHOD CS116
79 11 January 1993
 MIL-STD-462D

Power
Input

LISN

Injection
Probe
5 cm
Monitor
Probe
5 cm

EUT Plotter

5 cm Measurement
Monitor Receiver
Probe A
5 cm
Injection
Probe Directional
Coupler Amplifier

Interconnecting
Cables
Measurement
Receiver Signal
Actual or Simulated B Generator
Loads and Signals

FIGURE CS116-2. Loop circuit impedance characterization.

METHOD CS116
11 January 1993 80
 MIL-STD-462D

5 cm 5 cm

Monitoring
Probe
Injection Power
Probe 5 cm 5 cm Input

Test Instrumentation
or
Termination Box
EUT LISN

Storage
Oscilloscope

Damped
Sinusoid
Generator

FIGURE CS116-3. Typical set up for bulk cable injection

of damped sinusoidal transients.

METHOD CS116
81/82 11 January 1993
 MIL-STD-462D

METHOD RE101

RADIATED EMISSIONS, MAGNETIC FIELD, 30 Hz TO 100 kHz

1. Purpose. This test method is to verify that the magnetic

field emissions from the EUT and its associated cabling do not
exceed specified requirements.

2. Test Equipment. The test equipment shall be as follows:

a. Measurement receivers

b. Data recording device

c. Loop sensor having the following specifications:

(1) Diameter: 13.3 cm

(2) Number of turns: 36

(3) Wire: 7-41 Litz (7 strand, No. 41

AWG)

(4) Shielding: Electrostatic

(5) Correction factor: To convert measurement

receiver readings expressed
in decibels above one
microvolt (dBµV) to decibels
above one picotesla (dBpT),
add the factor shown in
Figure RE101-1.

d. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 2 through 5 and paragraph 4.8 of the
general section of this standard.

b. Calibration. Configure the measurement setup as shown in

Figure RE101-2.

c. EUT Testing. Configure the measurement receiving loop

and EUT as shown in Figure RE101-3.

METHOD RE101
83 11 January 1993
 MIL-STD-462D

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the measurement equipment and allow sufficient

time for stabilization.

b. Calibration.

(1) Apply a calibrated signal level, which is 6 dB below

the MIL-STD-461 limit, at a frequency of 50 kHz.
Tune the measurement receiver to a center frequency
of 50 kHz. Record the measured level.

(2) Verify that the measurement receiver indicates a

level within ±3 dB of the injected signal level.

(3) If readings are obtained which deviate by more than

±3 dB, locate the source of the error and correct the
deficiency prior to proceeding with the testing.

c. EUT Testing.

(1) Turn on the EUT and allow sufficient time for

stabilization.

(2) Locate the loop sensor 7 cm from the EUT face or

cable being probed. Orient the plane of the loop
sensor parallel to the EUT faces and parallel to the
axis of cables.

(3) Scan the measurement receiver over the applicable

frequency range to locate the frequencies of maximum
radiation, using the bandwidths and minimum
measurement times of the general section of this
standard.

(4) Tune the measurement receiver to one of the

frequencies or band of frequencies identified in
4c(3) above.

(5) Monitor the output of the measurement receiver while

moving the loop sensor (maintaining the 7 cm spacing)
over the face of the EUT or along the cable. Note
the point of maximum radiation for each frequency
identified in 4c(4).

(6) At 7 cm from the point of maximum radiation, orient

the plane of the loop sensor to give a maximum

METHOD RE101
11 January 1993 84
 MIL-STD-462D

reading on the measurement receiver and record the

reading.

(7) Move the loop sensor away from the EUT face or the
cable being probed to a distance of 50 cm and record
the reading on the measurement receiver.

(8) Repeat 4c(4) through 4c(7) for at least two

frequencies of maximum radiation per octave
of frequencies below 200 Hz and for at least three
frequencies of maximum radiation per octave above
200 Hz.

(9) Repeat 4c(2) through 4c(8) for each face of the EUT
and for each cable connected to the EUT.

5. Data Presentation. Data presentation shall be as follows:

a. Provide graphs or a tabular listing of each measurement

frequency, mode of operation, distance from the EUT,
measured magnetic field, and magnetic field limit level
for both the 7 cm and 50 cm distances.

METHOD RE101
85 11 January 1993
 MIL-STD-462D

100

90

80
Correction Factor (dBpT/µV)

70

60

50

40
RECEIVER
IMPEDANCE
30
50 Ω
20

10 600 Ω OR
GREATER

10 100 1k 10k 100k

Frequency (Hz)

FIGURE RE101-1. Loop sensor correction factor.

METHOD RE101
11 January 1993 86
 MIL-STD-462D

Coaxial
Measurement Cable Signal
Receiver Generator

FIGURE RE101-2. Calibration configuration.

METHOD RE101
87 11 January 1993
 MIL-STD-462D

Power
Input

LISN

7 cm

Receiving
Loop

Measurement
Receiver EUT

FIGURE RE101-3. Typical Test Setup for Radiated

Emissions, Magnetic Field, 30 Hz to
100 kHz.

METHOD RE101
11 January 1993 88
 MIL-STD-462D

METHOD RE102

RADIATED EMISSIONS, ELECTRIC FIELD, 10 kHz TO 18 GHz

1. Purpose. This test method is used to verify that electric

field emissions from the EUT and its associated cabling do not
exceed specified requirements.

2. Test Equipment. The test equipment shall be as follows:

a. Measurement receivers

b. Data recording device

c. Antennas

(1) 10 kHz to 30 MHz, 104 cm rod with impedance matching

network

(a) When the impedance matching network includes a

preamplifier (active rod), observe the overload
precautions in 4.7.3 of the general section of
this standard.

(b) Use a square counterpoise measuring at least

60 cm on a side.

(2) 30 MHz to 200 MHz, Biconical, 137 cm tip to tip

(3) 200 MHz to 18 GHz, Double ridge horns

d. Signal generators

e. Stub radiator

f. Capacitor, 10 pF

g. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 1 through 5 and paragraph 4.8 of the
general section of this standard. Ensure that the EUT is
oriented such that the surface which produces the maximum
radiated emissions is toward the measurement antenna.

METHOD RE102
89 11 January 1993
 MIL-STD-462D

b. Calibration. Configure the test equipment as shown in

Figure RE102-1.

c. EUT testing.

(1) For shielded room measurements, electrically bond the

rod antenna counterpoise to the ground plane using a
solid metal sheet the same width as the counterpoise.
The maximum DC resistance between the counterpoise
and the ground plane shall be 2.5 milliohms. For
bench top setups using a metallic ground plane, bond
the counterpoise to this ground plane. Otherwise,
bond the counterpoise to the floor ground plane. For
measurements outside a shielded enclosure,
electrically bond the counterpoise to earth ground.

(2) Antenna Positioning.

(a) Determine the test setup boundary of the EUT and

associated cabling for use in positioning of
antennas.

(b) Use the physical reference points on the antennas

shown in Figure RE102-2 for measuring heights of
the antennas and distances of the antennas from
the test setup boundary.

1. Position antennas 1 meter from the front edge

of the test setup boundary for all setups.

2. Position antennas other than the 104 cm rod

antenna 120 cm above the floor ground plane.

3. Insure that no part of any antenna is closer

than 1 meter from the walls and 0.5 meter
from the ceiling of the shielded enclosure.

4. For test setups using bench tops, additional

positioning requirements for the rod antenna
and distance above the bench ground plane are
shown in Figure RE102-2.

5. For free standing setups, electrically bond

and mount the 104 cm rod antenna matching
network to the floor ground plane without a
separate counterpoise.

METHOD RE102
11 January 1993 90
 MIL-STD-462D

(c) The number of required antenna positions depends

on the size of the test setup boundary and the
number of enclosures included in the setup.

1. For testing below 200 MHz, use the following

criteria to determine the individual antenna
positions.

a. For setups with the side edges of the

boundary 3 meters or less, one position is
required and the antenna shall be centered
with respect to the side edges of the
boundary.

b. For setups with the side edges of the

boundary greater than 3 meters, use
multiple antenna positions at spacings as
shown in Figure RE102-3. Determine the
number of antenna positions (N) by
dividing the edge-to-edge boundary
distance (in meters) by 3 and rounding up
to an integer.

2. For testing from 200 MHz up to 1 GHz, place

the antenna in a sufficient number of
positions such that the entire width of each
EUT enclosure and the first 35 cm of cables
and leads interfacing with the EUT enclosure
are within the 3 dB beamwidth of the antenna.

3. For testing at 1 GHz and above, place the

antenna in a sufficient number of positions
such that the entire width of each EUT
enclosure and the first 7 cm of cables and
leads interfacing with the EUT enclosure are
within the 3 dB beamwidth of the antenna.

4. Test Procedures. The test procedures shall be as follows:

a. Verify that the ambient requirements specified in 4.4 of

the general section of this standard are met. Take plots
of the ambient when required by the referenced paragraph.

b. Turn on the measurement equipment and allow a sufficient

time for stabilization.

c. Using the system check path of Figure RE102-1, perform

the following evaluation of the overall measurement

METHOD RE102
91 11 January 1993
 MIL-STD-462D

system from each antenna to the data output device at the

highest measurement frequency of the antenna. For rod
antennas that use passive matching networks, the
evaluation shall be performed at the center frequency of
each band.

(1) Apply a calibrated signal level, which is 6 dB below

the MIL-STD-461 limit (limit minus antenna factor),
to the coaxial cable at the antenna connection point.

(2) Scan the measurement receiver in the same manner as a

normal data scan. Verify that the data recording
device indicates a level within ±3 dB of the injected
signal level.

(3) For the 104 cm rod antenna, remove the rod element
and apply the signal to the antenna matching network
through a 10 pF capacitor connected to the rod mount.

(4) If readings are obtained which deviate by more than

±3 dB, locate the source of the error and correct the
deficiency prior to proceeding with the testing.

d. Using the measurement path of Figure RE102-1, perform the

following evaluation for each antenna to demonstrate that
there is electrical continuity through the antenna.

(1) Radiate a signal using an antenna or stub radiator at

the highest measurement frequency of each antenna.

(2) Tune the measurement receiver to the frequency of the

applied signal and verify that a received signal of
appropriate amplitude is present.

e. Turn on the EUT and allow sufficient time for

stabilization.

f. Using the measurement path of Figure RE102-1, determine

the radiated emissions from the EUT and its associated
cabling.

(1) Scan the measurement receiver for each applicable

frequency range, using the bandwidths and minimum
measurement times in the general section of this
standard.

(2) Above 30 MHz, orient the antennas for both

horizontally and vertically polarized fields.

METHOD RE102
11 January 1993 92
 MIL-STD-462D

(3) Take measurements for each antenna position

determined under 3c(2)(c) above.

5. Data Presentation. Data presentation shall be as follows:

a. Continuously and automatically plot amplitude versus

frequency profiles. Manually gathered data is not
acceptable except for plot verification.

b. Display the applicable limit on each plot.

c. Provide a minimum frequency resolution of 1% or twice the

measurement receiver bandwidth, whichever is less
stringent, and a minimum amplitude resolution of 1 dB for
each plot.

d. Provide plots for both the measurement and system check

portions of the procedure.

e. Provide a statement verifying the electrical continuity

of the measurement antennas as determined in 4d.

METHOD RE102
93 11 January 1993
 MIL-STD-462D

TEST SETUP BOUNDARY

Antenna

Path for
Measurement

Signal
Generator

Path for
System Check
Shielded Enclosure

Coaxial
Cable

Measurement
Receiver

Data
Recording
Device

FIGURE RE102-1. Basic test setup.

METHOD RE102
11 January 1993 94
 MIL-STD-462D

Test Setup Bonding

Boundary Strap

ROD
80-90 cm

Ground Counterpoise
Plane

Floor

Test Setup
Boundary

120 cm BICONICAL
80-90 cm

Ground
Plane

Floor

Test Setup
Boundary

DOUBLE
RIDGE HORN
120 cm
80-90 cm

Ground
Plane

Floor

1m

FIGURE RE102-2. Antenna positioning.

METHOD RE102
95 11 January 1993
 X

TEST SETUP BOUNDARY

METHOD RE102
X (in meters)
N= Rounded Up to an Integer
3

11 January 1993
X X X X
2N N N 2N 1m

FIGURE RE102-3.
Antenna
Positions

96
MIL-STD-462D

EXAMPLE: X = 4 m N=2 To
Loads
Actual
EUT Platform EUT
Length LISN
<2m
2m
2m 1m

Multiple antenna positions.

1m 2m 1m
 MIL-STD-462D

METHOD RE103

RADIATED EMISSIONS, ANTENNA SPURIOUS AND HARMONIC OUTPUTS,

10 kHz TO 40 GHz

1. Purpose. This test method is used to verify that radiated

spurious and harmonic emissions from transmitters do not exceed
the specified requirements.

2. Test Equipment. The test equipment shall be as follows:

a. Measurement receiver

b. Attenuators

c. Antennas

d. Rejection networks

e. Signal generators

f. Power monitor

3. Test Setup. It is not necessary to maintain the basic test

setup for the EUT as shown and described in figures 1 through 5
and paragraph 4.8 of the general section of this standard. The
test setup shall be as follows:

a. Calibration. Configure the test setup for the signal

check path shown in Figure RE103-1 or RE103-2 as
applicable.

b. EUT Testing. Configure the test setup for the

measurement path shown in Figure RE103-1 or RE103-2 as
applicable.

4. Test Procedures. The test procedures shall be as follows:

a. The measurements must be performed in the far-field of

the transmitting frequency. Consequently, the far-field
test distance must be calculated prior to performing the
test using the relationships below:

METHOD RE103
97 11 January 1993
 MIL-STD-462D

R = distance between transmitter antenna and receiver

antenna.
D = maximum physical dimension of transmitter antenna.
d = maximum physical dimension of receiver antenna.
λ = wavelength of frequency of the transmitter.

All dimensions are in meters.

For transmitter frequencies less than or equal to

1.24 GHz, the greater distance of the following
relationships shall be used:

R = 2D2/λ R = 3λ

For transmitter frequencies greater than 1.24 GHz, the

separation distance shall be calculated as follows:

For 2.5 D < d use R = 2D2/λ

For 2.5 D ≥ d use R = (D+d)2/λ

b. Turn on the measurement equipment and allow sufficient

time for stabilization.

c. Calibration.

(1) Apply a known calibrated signal level from the signal

generator through the system check path at a midband
fundamental frequency (fo) in accordance with the
general section of this standard.

(2) Scan the measurement receiver in the same manner as a

normal data scan. Verify the measurement receiver
detects a level within ±3 dB of the expected signal.

(3) If readings are obtained which deviate by more than

±3 dB, locate the source of the error and correct the
deficiency prior to proceeding with the test.

(4) Repeat 4c(1) through 4c(3) for two other frequencies

over the frequency range of test.

d. EUT Testing.

(1) Turn on the EUT and allow a sufficient time for

stabilization.

METHOD RE103
11 January 1993 98
 MIL-STD-462D

(2) Tune the EUT to the desired test frequency and use
the measurement path to complete the rest of this
procedure.

(3) Tune the test equipment to the measurement frequency

(fo) of the EUT and adjust for maximum indication.

(4) Measure the modulated transmitter power output P,

using a power monitor while keying the transmitter.
Convert this power level to units of dB relative to
1 watt (dBW). Calculate the Effective Radiated Power
(ERP) by adding the EUT antenna gain to this value.
Record the resulting level for comparison with that
obtained in 4d(6).

(5) Key the transmitter with desired modulation. Tune

the measurement receiver for maximum output
indication at the transmitted frequency. If either
or both of the antennas have directivity, align both
in elevation and azimuth for maximum indication.
Verbal communication between sites via radiotelephone
will facilitate this process. Record the resulting
maximum receiver meter reading and the measurement
receiver bandwidth.

(6) Calculate the transmitter ERP in dBW, based on the

receiver meter reading V, using the following
equation:

ERP = V + 20 log R + AF - 135

where:
V = reading on the measurement receiver in dBµV
R = distance between transmitter and receiver
antennas in meters
AF= antenna factor of receiver antenna in dB (1/m)

Compare this calculated level to the measured level

recorded in 4d(4). The compared results should agree
within ±3 dB. If the difference exceeds ±3 dB, check
the test setup for errors in measurement distance,
amplitude calibration, power monitoring of the
transmitter, frequency tuning or drift and antenna
boresight alignment. Assuming that the results are
within the ±3 dB tolerance, the ERP becomes the
reference for which amplitudes of spurious and
harmonics will be compared to determine compliance
with standard limits.

METHOD RE103
99 11 January 1993
 MIL-STD-462D

(7) With the rejection network filter connected and tuned

to fo, scan the measurement receiver over the
frequency range of test to locate spurious and
harmonic transmitted outputs. It may be necessary to
move the measuring system antenna in elevation and
azimuth at each spurious and harmonic output to
assure maximum levels are recorded. Maintain the
same measurement receiver bandwidth used to measure
the fundamental frequency in 4d(5).

(8) Verify that spurious outputs are from the EUT and not
spurious responses of the measurement system or the
test site ambient.

(9) Calculate the ERP of each spurious output. Include

all correction factors for cable loss, amplifier
gains, filter loss, and attenuator factors.

(10) Repeat 4d(2) through 4d(9) for other fo of the EUT.

5. Data Presentation. Data presentation shall be as follows:

a. Provide tabular data showing fundamental frequency (fo)

and frequency of all harmonics and spurious emissions
measured, the measured power monitor level and the
calculated ERP of the fundamental frequency, the ERP of
all spurious and harmonics emissions measured, dB down
levels, and all correction factors including cable loss,
attenuator pads, amplifier gains, insertion loss of
rejection networks and antenna gains.

b. The relative dB down level is determined by subtracting

the level in 4d(6) from that recorded in 4d(9).

METHOD RE103
11 January 1993 100
 MIL-STD-462D

TX Antenna RX Antenna
Path for Measurement

Path for Band Rejection

System or
Check High Pass Filter
Transmitter
EUT

Signal
Generator

Power
Monitor

Attenuator

Measurement
Receiver

FIGURE RE103-1. Calibration and test setup for radiated

harmonics and spurious emissions, 10 kHz
to 1 GHz.

METHOD RE103
101 11 January 1993
 MIL-STD-462D

TX Antenna RX Antenna
Path for Measurement

Path for Band Rejection

System or
Check High Pass Filter
Transmitter
EUT

Signal
Generator

Power
Monitor
Preselector
or Filter

Variable
Attenuator

Measurement
Receiver

FIGURE RE103-2. Calibration and test setup for radiated

harmonics and spurious emissions, 1 GHz
to 40 GHz.

METHOD RE103
11 January 1993 102
 MIL-STD-462D

METHOD RS101

RADIATED SUSCEPTIBILITY, MAGNETIC FIELD, 30 Hz TO 100 kHz

1. Purpose. This test method is to verify the ability of the

EUT to withstand radiated magnetic fields.

2. Test Equipment. The test equipment shall be as follows:

a. Signal source

b. Radiating loop having the following specifications:

(1) Diameter: 12 cm

(2) Number of turns: 20

(3) Wire: No. 12 insulated copper

(4) Magnetic flux density: 9.5x107 pT/ampere of applied

current at a distance of 5 cm
from the plane of the loop.

c. Loop sensor having the following specifications:

(1) Diameter: 4 cm

(2) Number of turns: 51

(3) Wire: 7-41 Litz (7 Strand, No. 41

AWG)

(4) Shielding: Electrostatic

(5) Correction Factor: To convert measurement

receiver readings expressed
in decibels above one
microvolt (dBµV) to decibels
above one picotesla (dBpT),
add the factor shown in
figure RS101-1.

d Measurement receiver or narrowband voltmeter

e. Current probe

f. LISNs

METHOD RS101
103 11 January 1993
 MIL-STD-462D

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 2 through 5 and paragraph 4.8 of the
general section of this standard.

b. Calibration.

(1) Configure the measurement equipment, radiating loop,

and loop sensor as shown in Figure RS101-2.

c. EUT Testing.

(1) Configure the test as shown in Figure RS101-3.

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the measurement equipment and allow sufficient

time for stabilization.

b. Calibration.

(1) Set the signal source to a frequency of 1 kHz and

adjust the output to provide a magnetic flux density
of 110 dB above one picotesla as determined by the
reading obtained on measurement receiver A and the
relationship given in 2b(4).

(2) Measure the voltage output from the loop sensor.

(3) Verify that the output on measurement receiver B is

42 dBµV ±3 dB and record this value in the
appropriate space on the data sheet.

c. EUT Testing.

(1) Turn on the EUT and allow sufficient time for

stabilization.

(2) Select test frequencies as follows:

(a) Position the radiating loop 5 cm from one face of

the EUT. The plane of the loop shall be parallel
to the plane of the EUT’s surface.

(b) Supply the loop with sufficient current to

produce magnetic field strengths at least 10 dB

METHOD RS101
11 January 1993 104
 MIL-STD-462D

greater than the applicable limit in MIL-STD-461

but not to exceed 15 amps (183 dBpT).

(c) Scan the applicable frequency range specified in

MIL-STD-461. Scan rates up to 3 times faster
than the rates specified in Table III are
acceptable.

(d) If susceptibility is noted, select no less than

three test frequencies per octave at those
frequencies where the maximum indications of
susceptibility are present.

(e) Reposition the loop successively to a location in

each 30 by 30 cm area on each face of the EUT and
at each electrical interface connector, and
repeat 4c(2)(c) and 4c(2)(d) to determine
locations and frequencies of susceptibility.

(f) From the total frequency data where

susceptibility was noted in 4c(2)(c) through
4c(2)(e), select three frequencies per octave
over the applicable frequency range in
MIL-STD-461.

(3) At each frequency determined in 4c(2)(f), apply a

current to the radiating loop that corresponds to the
applicable limit in MIL-STD-461. Move the loop to
search for possible locations of susceptibility with
particular attention given to the locations
determined in 4c(2)(e) while maintaining the loop
5 cm from the EUT surface, cable, or connector.
Verify that susceptibility is not present.

5. Data Presentation. Data presentation shall be as follows:

a. Provide tabular data showing verification of the

calibration of the radiating loop in 4a.

b. Provide tabular data, diagrams, or photographs showing

the applicable test frequencies and locations determined
in 4c(2)(e) and 4c(2)(f).

c. Provide graphical or tabular data showing frequencies and

threshold levels of susceptibility.

METHOD RS101
105 11 January 1993
 MIL-STD-462D

110

100

90
Correction Factor (dBpT/µV)

80

70

60

50 RECEIVER
IMPEDANCE
40
50 Ω
30
600 Ω OR
20 GREATER

10 100 1k 10k 100k

Frequency (Hz)

FIGURE RS101-1. Loop sensor correction factor.

METHOD RS101
11 January 1993 106
 MIL-STD-462D

5c
m

Radiating
Loop

Signal
Source
Current
Probe

Field
Monitoring
Loop

Measurement
Receiver A

Measurement
Receiver B

FIGURE RS101-2. Calibration of the radiating system.

METHOD RS101
107 11 January 1993
 MIL-STD-462D

Input Stimulation
and Monitoring
Equipment

Power
Input

5 cm
LISN
Radiating
Loop

Signal
Source EUT

Current
Probe

Measurement
Receiver

Output Stimulation
and Monitoring
Equipment

FIGURE RS101-3. Typical test setup for radiated

susceptibility. Magnetic field, 30 Hz to
50 kHz.

METHOD RS101
11 January 1993 108
 MIL-STD-462D

METHOD RS103

RADIATED SUSCEPTIBILITY, ELECTRIC FIELD, 10 kHz TO 40 GHz

1. Purpose. This test method is used to verify the ability of

the EUT and associated cabling to withstand electric fields.

2. Test Equipment. The test equipment shall be as follows:

a. Signal generators

b. Power amplifiers

c. Receive antennas

(1) 1 GHz to 10 GHz, double ridge horns

(2) 10 GHz to 40 GHz, other antennas as approved by the

procuring activity

d. Transmit antennas

e. Electric field sensors (physically small - electrically

short)

f. Measurement receiver

g. Power meter

h. Directional coupler

i. Attenuator

j. Data recording device

k. LISNs

3. Test Setup. The test setup shall be as follows:

a. Maintain a basic test setup for the EUT as shown and

described in Figures 1 through 5 and paragraph 4.8 of the
general section of this standard.

b. For electric field calibration, electric field sensors

are required from 10 kHz to 1 GHz. Either field sensors
or receive antennas may be used above 1 GHz (see 2c and
2e).

METHOD RS103
109 11 January 1993
 MIL-STD-462D

c. Configure test equipment as shown in Figure RS103-1.

d. Calibration.

(1) Placement of electric field sensors (see 3b).

Position sensors 1 meter from, and directly opposite,
the transmit antenna as shown in Figures RS103-2 and
RS103-3. Do not place sensors directly at corners or
edges of EUT components.

(2) Placement of receive antennas (see 3b). Prior to

placement of the EUT, position the receive antenna,
as shown in Figure RS103-4, on a dielectric stand at
the position and height above the ground plane where
the center of the EUT will be located.

e. EUT testing.

(1) Placement of transmit antennas. Antennas shall be

placed 1 meter from the test setup boundary as
follows:

(a) 10 kHz to 200 MHz

1 Test setup boundaries ≤ (less than or equal

to) 3 meters. Center the antenna between the
edges of the test setup boundary. The
boundary includes all enclosures of the EUT
and the 2 meters of exposed interconnecting
and power leads required by the general
section of this standard. Interconnecting
leads shorter than 2 meters are acceptable
when they represent the actual platform
installation.

2 Test setup boundaries > (greater than)

3 meters. Use multiple antenna positions (N)
at spacings as shown in Figure RS103-3. The
number of antenna positions (N) shall be
determined by dividing the edge-to-edge
boundary distance (in meters) by 3 and
rounding up to an integer.

(b) 200 MHz and above. Multiple antenna positions

may be required as shown in Figure RS103-2.
Determine the number of antenna positions (N) as
follows:

METHOD RS103
11 January 1993 110
 MIL-STD-462D

1 For testing from 200 MHz up to 1 GHz, place

the antenna in a sufficient number of
positions such that the entire width of each
EUT enclosure and the first 35 cm of cables
and leads interfacing with the EUT enclosure
are within the 3 dB beamwidth of the antenna.

2 For testing at 1 GHz and above, place the

antenna in a sufficient number of positions
such that the entire width of each EUT
enclosure and the first 7 cm of cables and
leads interfacing with the EUT enclosure are
within the 3 dB beamwidth of the antenna.

(2) Maintain the placement of electric field sensors as

specified in 3e(1) above.

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the measurement equipment and EUT and allow a

sufficient time for stabilization.

b. Assess the test area for potential RF hazards and take

necessary precautionary steps to assure safety of test
personnel.

c. Calibration.

(1) Electric field sensor method. Record the amplitude

shown on the electric field sensor display unit due
to EUT ambient. Reposition the sensor, as necessary,
until this level is < 10% of the applicable field
strength to be used for testing.

(2) Receive antenna method (> 1 GHz).

(a) Connect a signal generator to the coaxial cable

at the receive antenna connection point (antenna
removed). Set the signal source to an output
level of 0 dBm at the highest frequency to be
used in the present test setup. Tune the
measurement receiver to the frequency of the
signal source.

(b) Verify that the output indication is within ±3 dB

of the applied signal, considering all
appropriate losses. If larger deviations are

METHOD RS103
111 11 January 1993
 MIL-STD-462D

found, locate the source of the error and correct

the deficiency before proceeding.

(c) Connect the receive antenna to the coaxial cable

as shown in Figure RS103-4. Set the signal
source to 1 kHz pulse modulation, 50% duty cycle.
Using an appropriate transmit antenna and
amplifier, establish an electric field at the
test start frequency. Gradually increase the
electric field level until it reaches the
applicable limit.

(d) Scan the test frequency range and record the

required input power levels to the transmit
antenna to maintain the required field.

(e) Repeat procedures (a) through (d) whenever the

test setup is modified or an antenna is changed.

d. EUT Testing.

(1) E-Field sensor method.

(a) Set the signal source to 1 kHz pulse modulation,

50% duty cycle, and using appropriate amplifier
and transmit antenna, establish an electric field
at the test start frequency. Gradually increase
the electric field level until it reaches the
applicable limit shown in MIL-STD-461.

(b) Scan the required frequency ranges in accordance

with the rates and durations specified in the
general section of this standard. Maintain field
strength levels in accordance with the applicable
limit. Monitor EUT performance for
susceptibility effects.

(2) Receive antenna method.

(a) Remove the receive antenna and reposition the EUT

in conformance with 3a.

(b) Set the signal source to 1 kHz pulse modulation,

50% duty cycle. Using an appropriate amplifier
and transmit antenna, establish an electric field
at the test start frequency. Gradually increase
the input power level until it corresponds to the

METHOD RS103
11 January 1993 112
 MIL-STD-462D

applicable level recorded during the calibration

routine.

(c) Scan the required frequency range in accordance

with the rates and durations specified in the
general section of this standard while assuring
the correct transmitter input power is adjusted
in accordance with the calibration data
collected. Constantly monitor the EUT for
susceptibility conditions.

(3) If susceptibility is noted, determine the level at

which the undesirable response is no longer present
and verify it is above the MIL-STD-461 requirement.

(4) Perform testing over the required frequency range

with the transmit antenna vertically polarized.
Repeat the testing above 30 MHz with the transmit
antenna horizontally polarized.

(5) Repeat 4d for each transmit antenna position required

by 3e.

5. Data Presentation. Data presentation shall be as follows:

a. Provide graphical or tabular data showing frequency

ranges and field strength levels tested.

b. Provide graphical or tabular data listing (antenna method

only) all calibration data collected to include input
power requirements used versus frequency, and results of
system check in 4c(2)(c) and 4c(2)(d).

c. Provide the correction factors necessary to adjust sensor

output readings for equivalent peak detection of
modulated waveforms.

d. Provide graphs or tables listing any susceptibility

thresholds which were determined along with their
associated frequencies.

e. Provide diagrams or photographs showing actual equipment

setup and the associated dimensions.

METHOD RS103
113 11 January 1993
 MIL-STD-462D

TEST SETUP BOUNDARY

Electric
Field
Sensor LISN

EUT

3m

1.5 m

Antenna

Shielded Enclosure

RF Stimulation
Amplifiers and Monitoring
Equipment

Signal Electric Field

Source Sensor Display

FIGURE RS103-1. Test equipment configuration.

METHOD RS103
11 January 1993 114
 MIL-STD-462D

TEST SETUP BOUNDARY

LISN Electric
Field
Sensor

EUT EUT EUT

N Antenna
Positions

Shielded Enclosure

RF Stimulation
Amplifiers and Monitoring
Equipment

Signal Electric Field

Source Sensor Display

FIGURE RS103-2. Multiple test antenna locations for

frequency > 200 MHz.

METHOD RS103
115 11 January 1993
 MIL-STD-462D

TEST SETUP BOUNDARY

D > 3 Meters

LISN

EUT EUT
N Electric Field Sensor
Positions

D D
N N

N Antenna Positions
Shielded Enclosure

RF Stimulation
Amplifiers and Monitoring
Equipment

Signal Electric Field

Source Sensor Display

FIGURE RS103-3. Multiple test antenna locations for

N positions, D > 3 meters.

METHOD RS103
11 January 1993 116
 MIL-STD-462D

TEST SETUP BOUNDARY

Signal
Generator
Path for
Measurement Path for
System Check

Receive
Antenna

Transmit
Antenna

Shielded Enclosure

Signal
Source Attenuator

RF Measurement
Amplifiers Receiver

Directional Data
Coupler Recorder

Power
Meter

Data
Recorder

FIGURE RS103-4. Receive antenna method (1 to 40 GHz).

METHOD RS103
117/118 11 January 1993
 MIL-STD-462D

METHOD RS105

RADIATED SUSCEPTIBILITY, TRANSIENT ELECTROMAGNETIC FIELD

1. Purpose. This test method is used to verify the ability of

the EUT enclosure to withstand a transient electromagnetic field.

2. Test Equipment. The test equipment shall be as follows:

a. Parallel plates, Transverse Electromagnetic (TEM) cell or

equivalent

b. Transient monopulse generator

c. Storage oscilloscope, 200 MHz minimum single shot

bandwidth and a variable sampling rate up to 1 gigasample
per second (GSa/s)

d. Terminal Protection Devices (TPDs)

e. High-voltage probe

f. B-Dot sensor and integrator

g. D-Dot sensor and integrator

h. LISNs

3. Test Setup. Maintain the basic test setup for the EUT as
described below. CAUTION: Exercise extreme care if an open
radiator is used for this test.

a. Calibration. Configure the test equipment in accordance

with Figure RS105-1.

(1) Place the B-Dot or D-Dot probe with integrator in the

middle of the empty radiation system. Connect the
probe to a storage oscilloscope.

(2) Place the high voltage probe across the radiation

system termination load. Connect the probe to a
storage oscilloscope.

b. EUT Testing. Configure the test equipment as shown in

Figure RS105-2 for testing of the EUT.

METHOD RS105
119 11 January 1993
 MIL-STD-462D

(1) Place the EUT enclosure on the bottom plate or ground

plane of the radiation system in a manner such that
it does not exceed the usable volume of the radiation
system as shown in Figure RS105-2. The separation
between radiating surfaces shall be at least three
times the height of the EUT.

(2) Bond the bottom plate of the radiation system to an

earth reference.

(3) Keep the top plate of the radiation system at least

2 times h from the closest metallic ground, where h
is the maximum vertical separation of the plates,
including ceiling, building structural beams,
metallic air ducts, shielded room walls, and so
forth.

(4) Place the test instrumentation in a shielded

enclosure when an open radiator is used.

(5) Use shielding to protect the cables.

(6) Place TPDs in the EUT power lines near the power
source to protect the power source.

(7) Connect the monopulse transient generator to the

radiation system.

4. Test Procedures. The test procedures shall be as follows:

a. Turn on the measurement equipment and allow a sufficient

time for stabilization.

b. Calibration. Perform the following procedures using the

calibration setup.

(1) Generate a single pulse. CAUTION: High voltages are

used which are potentially lethal.

(2) Observe the pulse to assure that rise time, peak

amplitude and decay criteria as specified are met.

c. EUT Testing. Test the EUT in its orthogonal orientations

whenever possible.

(1) Turn on the EUT and allow a sufficient time for

stabilization.

METHOD RS105
11 January 1993 120
 MIL-STD-462D

(2) Apply the pulse starting at 50% of the required peak

level with the specified waveshape. Increase the
pulse amplitude slowly until the required level is
reached.

(3) Apply the required number of pulses at a rate of not

more than 1 pulse per minute.

(4) Monitor the applied pulse using at least one of the

calibration probes and storage oscilloscope.

(5) Monitor the EUT during and after the application of

each pulse for signs of susceptibility or degradation
of performance.

(6) If an EUT malfunction occurs at a level less than the

specified peak level, terminate the test and record
the level.

(7) If susceptibility is noted, determine the level at

which the undesirable response is no longer present
and verify that it is above the MIL-STD-461
requirement.

5. Data Presentation. Data presentation shall be as follows:

a. Provide photographs of EUT orientation including cables.

b. Provide detailed written description of the EUT

configuration.

c. Provide representative oscilloscope photographs of

transient waveshape, including peak value, rise and decay
times linearly recorded for each applied test transient.
Analog time domain X-Y recordings taken from an analog or
digitizing oscilloscope are also acceptable.

d. Provide the pulse number, with the first pulse being

Number 1, for each recorded waveshape.

e. Record the time-to-recovery for each EUT failure, if

applicable.

METHOD RS105
121 11 January 1993
 MIL-STD-462D

Transient
Load
Generator Parallel Plate
Line High Voltage
Probe

Shielded
Sensor Enclosure

Integrator Oscilloscope

FIGURE RS105-1. Typical calibration setup using parallel

plate radiation system.

METHOD RS105
11 January 1993 122
 MIL-STD-462D

TOP VIEW

Integrator

Oscilloscope

Shielded
Enclosure

A
Load
Transient
Pulse A/2
Generator

B B/2 EUT

High Voltage
Sensor Probe

Usable Test Volume Cable in Conduit

(Centered on Bottom Plate) (Beneath Bottom Plate)

Power Line

Test Sample
LISN Instrumentation

TPDs
Shielded
Enclosure
Power Input

FIGURE RS105-2. Typical test setup using parallel plate

radiation system.

METHOD RS105
123/124 11 January 1993
 MIL-STD-462D

CONCLUDING MATERIAL

Custodians:

Army - CR Preparing Activity:

Navy - EC Air Force - 11
(Project EMCS-0134)

Review Activities:

Army - MI, AV, TE

Navy - SH, AS, OS, YD, MC, CG, TD
Air Force - 13, 15, 17, 19, 99
NSA

User Activities:

Air Force - 84
Army - AT, ME, CE, CL, MD
DISA
DODECAC
DNA

125/126
 MIL-STD-462D
APPENDIX

APPENDIX

MIL-STD-462D
APPLICATION GUIDE

A-1
 MIL-STD-462D
APPENDIX

CONTENTS

PARAGRAPH PAGE

10. GENERAL . . . . . . . . . . . . . . . . . . . . . A-5

10.1 Scope . . . . . . . . . . . . . . . . . . . . . A-5
10.2 Structure . . . . . . . . . . . . . . . . . . . A-5

20. APPLICABLE DOCUMENTS . . . . . . . . . . . . . . . A-6

20.1 Government documents . . . . . . . . . . . . . A-6
20.1.1 Specifications, standards, and handbooks . . . A-6
20.1.2 Other Government documents, drawings, and
publications . . . . . . . . . . . . . . . . . A-6
20.2. Non-Government publications . . . . . . . . . . A-7

30. DEFINITIONS . . . . . . . . . . . . . . . . . . . A-9

30.1 General . . . . . . . . . . . . . . . . . . . . A-9
30.2 Acronyms used in this appendix . . . . . . . . A-9
30.3 Metric units . . . . . . . . . . . . . . . . . A-9
30.4 Test setup boundary . . . . . . . . . . . . . . A-9

40. REQUIREMENTS . . . . . . . . . . . . . . . . . . . A-10

40.1 (4.1) General . . . . . . . . . . . . . . . . . A-10
40.1.1
1 (4.1.1) Measurement tolerances . . . . . . . . A-10
40.2 (4.2) Shielded enclosures . . . . . . . . . . . A-10
40.2.1 (4.2.1) Radio Frequency (RF) absorber material A-11
40.3 (4.3) Other test sites . . . . . . . . . . . . A-12
40.4 (4.4) Ambient electromagnetic level . . . . . . A-12
40.5 (4.5) Ground plane . . . . . . . . . . . . . . A-14
40.5.1 (4.5.1) Metallic ground plane . . . . . . . . . A-14
40.5.2 (4.5.2) Composite ground plane . . . . . . . . A-15
40.6 (4.6) Power source impedance . . . . . . . . . A-15
40.7 (4.7) General test precautions . . . . . . . . A-17
40.7.1 (4.7.1) Accessory equipment . . . . . . . . . . A-18
40.7.2 (4.7.2) Excess personnel and equipment . . . . A-18
40.7.3 (4.7.3) Overload precautions . . . . . . . . . A-19
40.7.4 (4.7.4) RF hazards . . . . . . . . . . . . . . A-20
40.7.5 (4.7.5) Shock hazard . . . . . . . . . . . . . A-20
40.7.6 (4.7.6) Federal Communication Commission (FCC)
restrictions . . . . . . . . . . . . . . . . . A-20
40.8 (4.8) EUT test configurations . . . . . . . . . A-21
40.8.1 (4.8.1) Bonding of EUT . . . . . . . . . . . . A-21
40.8.2 (4.8.2) Shock and vibration isolators . . . . . A-21
40.8.3 (4.8.3) Wire grounds . . . . . . . . . . . . . A-22
40.8.4 (4.8.4) Orientation of EUTs . . . . . . . . . . A-22
40.8.5 (4.8.5) Construction and arrangement of EUT
cables . . . . . . . . . . . . . . . . . . . . A-23
40.8.5.1 (4.8.5.1) Interconnecting leads and cables . . A-24
40.8.5.2 (4.8.5.2) Input power leads . . . . . . . . . . A-25
40.8.6 (4.8.6) Electrical and mechanical interfaces . A-26

A-2
 MIL-STD-462D
APPENDIX

CONTENTS

PARAGRAPH PAGE

40.9 (4.9) Operation of EUT . . . . . . . . . . . . A-27

40.9.1 (4.9.1) Operating frequencies for tunable
RF equipment . . . . . . . . . . . . . . . . . A-27
40.9.2 (4.9.2) Operating frequencies for spread
spectrum equipment . . . . . . . . . . . . . . A-28
40.9.3 (4.9.3) Susceptibility monitoring . . . . . . . A-28
40.10 (4.10) Use of measuring equipment . . . . . . . A-29
40.10.1 (4.10.1) Detector . . . . . . . . . . . . . . . A-30
40.10.2 (4.10.2) Computer-controlled receivers . . . . A-32
40.10.3 (4.10.3) Emission testing . . . . . . . . . . . A-32
40.10.3.1 (4.10.3.1) Bandwidths . . . . . . . . . . . . . A-32
40.10.3.2 (4.10.3.2) Emission identification . . . . . . A-33
40.10.3.3 (4.10.3.3) Frequency scanning . . . . . . . . . A-34
40.10.3.4 (4.10.3.4) Emission data presentation . . . . . A-35
40.10.4 (4.10.4) Susceptibility testing . . . . . . . . A-37
40.10.4.1 (4.10.4.1) Frequency scanning . . . . . . . . . A-37
40.10.4.2 (4.10.4.2.) Modulation of susceptibility
signals . . . . . . . . . . . . . . . . . . . . A-41
40.10.4.3 (4.10.4.3) Thresholds of susceptibility . . . . A-42
40.11 (4.11) Calibration of measuring equipment and
antennas . . . . . . . . . . . . . . . . . . . A-42
40.11.1 (4.11.1) Measurement system test . . . . . . . A-43
40.12 (4.12) Antenna factors . . . . . . . . . . . . A-43

50.0 MEASUREMENT PROCEDURES . . . . . . . . . . . . . . . . A-44

TEST METHOD CE101 . . . . . . . . . . . . . . . . . . . . . A-44

TEST METHOD CE102 . . . . . . . . . . . . . . . . . . . . . A-44
TEST METHOD CE106 . . . . . . . . . . . . . . . . . . . . . A-46
TEST METHOD CS101 . . . . . . . . . . . . . . . . . . . . . A-47
TEST METHOD CS103 . . . . . . . . . . . . . . . . . . . . . A-49
TEST METHOD CS104 . . . . . . . . . . . . . . . . . . . . . A-51
TEST METHOD CS105 . . . . . . . . . . . . . . . . . . . . . A-54
TEST METHOD CS109 . . . . . . . . . . . . . . . . . . . . . A-56
TEST METHOD CS114 . . . . . . . . . . . . . . . . . . . . . A-56
TEST METHOD CS115 . . . . . . . . . . . . . . . . . . . . . A-60
TEST METHOD CS116 . . . . . . . . . . . . . . . . . . . . . A-62
TEST METHOD RE101 . . . . . . . . . . . . . . . . . . . . . A-63
TEST METHOD RE102 . . . . . . . . . . . . . . . . . . . . . A-64
TEST METHOD RE103 . . . . . . . . . . . . . . . . . . . . . A-66
TEST METHOD RS101 . . . . . . . . . . . . . . . . . . . . . A-67
TEST METHOD RS103 . . . . . . . . . . . . . . . . . . . . . A-68
TEST METHOD RS105 . . . . . . . . . . . . . . . . . . . . . A-71

A-3
 MIL-STD-462D
APPENDIX

TABLE PAGE

I Absorption at Normal Incidence . . . . . . . . . . A-12

II Bandwidth and Measurement Time . . . . . . . . . . A-33
III Susceptibility Scanning . . . . . . . . . . . . . A-38
A-I Susceptibility Testing Times . . . . . . . . . . . A-40

FIGURE

A-1 Peak detector response . . . . . . . . . . . . . . A-31

A-2 Example of data presentation resolution . . . . . A-37
A-3 Correction factor for LISN capacitor . . . . . . . A-45
A-4 CS101 Power amplifier protection . . . . . . . . . A-48
A-5 CS103 General test setup . . . . . . . . . . . . . A-50
A-6 CS104 General test setup . . . . . . . . . . . . . A-53
A-7 CS105 General test setup . . . . . . . . . . . . . A-55
A-8 Typical CS114 calibration fixture . . . . . . . . A-58
A-9 Typical insertion loss of CS114 injection probes . A-59
A-10 Circuit diagram of CS115 pulse generator . . . . . A-60
A-11 Typical CS115 calibration fixture waveform . . . . A-61

A-4
 MIL-STD-462D
APPENDIX

10. GENERAL

10.1 Scope. This appendix provides background information

for each requirement in the main body of the standard. The
information includes rationale for the test requirements and
guidance for application of the requirements. This information
should help users understand the intent behind the test
requirements and adapt them in the Electromagnetic Interference
Test Procedures (EMITP) as necessary for particular applications.
This appendix is provided for guidance purposes and, as such,
should not be interpreted as providing contractual requirements.

10.2 Structure. This appendix follows the same general

format as the main body of the standard. A "DISCUSSION"
paragraph is provided for each requirement contained in the
standard.

A-5
 MIL-STD-462D
APPENDIX

20. APPLICABLE DOCUMENTS

20.1 Government documents.

20.1.1 Specifications, standards, and handbooks. The

following specifications, standards, and handbooks form a part of
this document to the extent specified herein. Unless otherwise
specified, the issues of these documents are those listed in the
issue of the Department of Defense Index of Specifications and
Standards (DODISS) and supplement thereto, cited in the
solicitation.

STANDARDS

MILITARY

MIL-STD-220 - Method of Insertion Loss

Measurement

MIL-STD-285 - Attenuation Measurements for

Enclosures, Electromagnetic
Shielding,for Electronic Test
Purposes, Method of

MIL-STD-461 - Requirements for the Control of

Electromagnetic Interference
Emissions and Susceptibility

MIL-STD-45662 - Calibration Systems Requirements

(Copies of federal and military specifications, standards, and

handbooks are available from the Director, Navy Publications and
Printing Service Office, 700 Robbins Avenue, Philadelphia, PA
19111-5093.)

20.1.2 Other Government documents, drawings, and

publications. The following other Government documents,
drawings, and publications form a part of this document to the
extent specified herein. Unless otherwise specified, the issues
are those cited in the solicitation.

DODISS - Department of Defense Index of

Specifications and Standards

(Copies of the DODISS are available on a yearly subscription

basis either from the Government Printing Office for hard copy,
or microfiche copies are available from the Director, Navy
Publications and Printing Service Office, 700 Robbins Avenue,
Philadelphia, PA 19111-5093.)

A-6
 MIL-STD-462D
APPENDIX

20.2. Non-Government publications. The following documents

form a part of this document to the extent specified herein.
Unless otherwise specified, the issues of the documents which are
DOD adopted are those listed in the issue of the DoDISS cited in
the solicitation. Unless otherwise specified, the issues of
documents not listed in the DODISS are the issues of the
documents cited in the solicitation.

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM E 380 - Standard for Metric Practice.

(DOD adopted)

(Application for copies should be addressed to the American

Society for Testing and Materials, 1916 Race Street,
Philadelphia, PA 19103-1187.)

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

ANSI/IEEE 268 - Metric Practice. (DOD adopted)

ANSI C63.2 - Standard for Instrumentation -

Electromagnetic
Noise and Field
Strength, 10 kHz to 40 GHz -
Specifications

ANSI C63.4 - Standard for Electromagnetic

Compatibility - Radio-Noise
Emissions from Low Voltage
Electrical and Electronic
Equipment in the Range of 9 kHz
to 1 GHz - Methods of Measurement

ANSI C63.14 - Standard Dictionary for

Technologies of Electromagnetic
Compatibility (EMC),
Electromagnetic Pulse (EMP), and
Electrostatic Discharge (ESD)

ANSI C95.1 - Standard for Safety Levels with

Respect to Human Exposure to
Radio Frequency Electromagnetic
Fields (300 kHz to 100 GHz)

(Application for copies should be addressed to the IEEE

Service Center, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ
08855-1331.)

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

A-7
 MIL-STD-462D
APPENDIX

National Electrical Code

(Application for copies of should be addressed to the National

Fire Protection Association, Batterymarch Park, Quincy, MA 02269-
9990.)

RADIO TECHNICAL COMMISSION FOR AERONAUTICS

DO-160 - Environmental Conditions and Test

Conditions for Airborne Equipment

(Application for copies should be addressed to Radio Technical

Commission for Aeronautics Secretariat, One McPherson Square,
Suite 500, 1425 K Street, NW, Washington DC 20005.)

SOCIETY OF AUTOMOTIVE ENGINEERS (SAE)

ARP 958 - Electromagnetic Interference

Measurement Antennas; Standard

Calibration Requirements and

Methods

ARP 1972 - Recommended Measurement Practices

and Procedures for EMC Testing

(Application for copies should be addressed to the Society of

Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale,
PA 15096.)

A-8
 MIL-STD-462D
APPENDIX

30. DEFINITIONS

30.1 General. The terms used in this appendix are defined in

ANSI C63.14. In addition, the following definitions are
applicable for the purposes of this appendix.

30.2 Acronyms used in this appendix.

a. BIT - Built-in-Test

b. CW - Continuous Wave

c. EMI - Electromagnetic Interference

d. EMITP - Electromagnetic Interference Test Procedures

e. EMITR - Electromagnetic Interference Test Report

f. EMP - Electromagnetic Pulse

g. ERP - Effective Radiated Power

h. EUT - Equipment Under Test

i. GPI - Ground Plane Interference

j. LISN - Line Impedance Stabilization Network

k. RF - Radio Frequency

l. RMS - Root Mean Square

m. TEM - Transverse Electromagnetic

n. VSWR - Voltage Standing Wave Ratio

30.3 Metric units. Metric units are a system of basic

measures which are defined by the International System of Units
based on "Le System International d’Unites (SI)", of the
International Bureau of Weights and Measures. These units are
described in ASTM E 380 and ANSI/IEEE 268.

30.4 Test setup boundary. The test setup boundary includes

all enclosures of the Equipment Under Test (EUT) and the 2 meters
of exposed interconnecting leads (except for leads which are
shorter in the actual installation) and power leads required by
the general section of this standard.

A-9
 MIL-STD-462D
APPENDIX

40. REQUIREMENTS

40.1 (4.1) General. General requirements related to test

methods, test facilities, and equipment are as stated below. Any
approved exceptions or deviations from these general test
requirements shall be documented in the EMITP required by
MIL-STD-461.

DISCUSSION: This portion of the document specifies

requirements that are applicable to a variety of test methods.
Individual test methods include requirements which are unique to
that test method only. Other sources of information dealing with
electromagnetic interference testing are available in industry
documents such as RTCA DO-160 and SAE ARP 1972.

40.1.1 (4.1.1) Measurement tolerances. Unless otherwise

stated for a particular measurement, the tolerance shall be as
follows:

a. Distance: +5%

b. Frequency: +2%

c. Amplitude, measurement receiver: +2 dB

d. Amplitude, measurement system (includes measurement

receivers, transducers, cables, and so forth): +3 dB

e. Time (waveforms): +5%

DISCUSSION: Tolerances are necessary to maintain reasonable

controls for obtaining consistent measurements. Paragraphs
4.1.4.b through 4.1.4.d are in agreement with ANSI C63.2 for
electromagnetic noise instrumentation.

40.2 (4.2) Shielded enclosures. To prevent interaction

between the Equipment Under Test (EUT) and the outside
environment, shielded enclosures will usually be required for
testing. These enclosures prevent external environment signals
from contaminating emission measurements and susceptibility test
signals from interfering with electrical and electronic items in
the vicinity of the test facility. Shielded enclosures must have
adequate attenuation such that the ambient requirements of
paragraph 4.4 are satisfied. The enclosures must be sufficiently
large such that the EUT arrangement requirements of paragraph 4.8
and antenna positioning requirements described in the individual
test methods are satisfied.

A-10
 MIL-STD-462D
APPENDIX

DISCUSSION: Potential accuracy problems introduced by

shielded enclosure resonances are well documented and recognized;
however, shielded enclosures are usually a necessity for testing
of military equipment to MIL-STD-461 requirements. Most test
agencies are at locations where ambient levels outside of the
enclosures are significantly above MIL-STD-461 limits and would
interfere with the ability to obtain meaningful data.

Electrical interfaces with military equipment are often

complex and require sophisticated test equipment to simulate and
evaluate the interface. This equipment usually must be located
outside of the shielded enclosure to achieve sufficient isolation
and prevent it from contaminating the ambient and responding to
susceptibility signals.

The shielded enclosure also prevents radiation of applied

susceptibility signals from interfering with local antenna-
connected receivers. The most obvious potential offender is the
RS103 test. However, other susceptibility tests can result in
substantial radiated energy which may violate Federal
Communication Commission (FCC) rules. Shielded enclosures with
the following characteristics will typically provide the required
isolation:

a. Shielding effectiveness of 80 decibels (dB) with respect

to electric fields and plane waves above 10 kHz as
measured in accordance with MIL-STD-285.

b. Powerline filtering of 80 dB attenuation at

frequencies above 10 kHz as measured in accordance
with MIL-STD-220.

40.2.1 (4.2.1) Radio Frequency (RF) absorber material. RF

absorber material (carbon impregnated foam pyramids, ferrite
tiles, and so forth) shall be used when performing electric field
radiated emission or radiated susceptibility testing inside a
shielded enclosure to reduce reflections of electromagnetic
energy and to improve accuracy and repeatability. The RF
absorber shall be placed above, behind, and on both sides of the
EUT, and behind the radiating or receiving antenna as shown in
Figure 1. Minimum performance of the material shall be as
specified in Table I. The manufacturer’s certification of their
RF absorber material (basic material only, not installed) is
acceptable.

DISCUSSION: Accuracy problems with making measurements in

untreated shielded enclosures due to reflections of
electromagnetic energy have been widely recognized and
documented. The values of RF absorption required by Table I are
considered to be sufficient to substantially improve the
integrity of the measurements without unduly impacting test

A-11
 MIL-STD-462D
APPENDIX

facilities. The minimum placement provisions for the material

are specified to handle the predominant reflections. The use of
additional material is desirable, where possible. It is intended
that the values in Table I can be met with available ferrite tile
material or standard 24 inch (0.61 meters) pyramidal absorber
material.

TABLE I. Absorption at Normal Incidence.

Frequency Minimum Absorption

80 MHz - 250 MHz 6 dB
above 250 MHz 10 dB

40.3 (4.3) Other test sites. If other test sites are used,
the ambient requirements of paragraph 4.4 shall be met.

DISCUSSION: For certain types of EUTs, testing in a shielded

enclosure may not be practical. Examples are EUTs which are
extremely large, require high electrical power levels or motor
drives to function, emit toxic fumes, contain explosives such as
squibs, or are too heavy for normal floor loading. There is a
serious concern with ambient levels contaminating data when
testing is performed outside of a shielded enclosure. Therefore,
special attention is given to this testing under paragraph 4.4,
"Ambient electromagnetic level." All cases where testing is
performed outside a shielded enclosure shall be justified in
detail in the EMITP including typical profiles of expected
ambient levels.

An option in emission testing is the use of an open area

test site (OATS) in accordance with ANSI C63.4. These sites are
specifically designed to enhance accuracy and repeatability.
Due to differences between ANSI C63.4 and this standard in areas
such as antenna selection, measurement distances, and specified
frequency ranges, the EMITP shall detail the techniques for using
the OATS and relating the test results to MIL-STD-461
requirements.

40.4 (4.4) Ambient electromagnetic level. During testing,

the ambient electromagnetic level measured with the EUT de-
energized and all auxiliary equipment turned on shall be at least
6 dB below the allowable specified limits when the tests are
performed in a shielded enclosure. Ambient conducted levels on
power leads shall be measured with the leads disconnected from
the EUT and connected to a resistive load which draws the same
rated current as the EUT. When tests are performed in a shielded
enclosure and the EUT is in compliance with MIL-STD-461 limits,
the ambient profile need not be recorded in the Electromagnetic

A-12
 MIL-STD-462D
APPENDIX

Interference Test Report (EMITR). When measurements are made

outside a shielded enclosure, the tests shall be performed during
times and conditions when the ambient is at its lowest level.
The ambient shall be recorded in the EMITR required by
MIL-STD-461 and shall not compromise the test results.

DISCUSSION: Controlling ambient levels is critical to

maintaining the integrity of the gathered data. High ambients
present difficulties distinguishing between EUT emissions and
ambient levels. Even when specific signals are known to be
ambient related, they may mask EUT emissions which are above
MIL-STD-461 limits.

The requirement that the ambient be at least 6 dB below the

limit ensures that the combination of the EUT emissions and
ambient does not unduly affect the indicated magnitude of the
emission. Since the EUT emissions are not phase coherent with
the ambient, the signals combine with the square root of the sum
of the squares of the individual voltage amplitudes. If a true
emission level is at the limit and the ambient is 6 dB below the
limit, the indicated level would be 1.0 dB above the limit.
Similarly, if the ambient were allowed to be equal to the limit
for the same true emission level, the indicated level would be
3.0 dB above the limit.

A resistive load is specified to be used for conducted

ambients on power leads. However, under certain conditions
actual ambient levels may be higher than indicated with a
resistive load. The most likely reason is the presence of
capacitance at the power interface of the EUT which will lower
the input impedance at higher frequencies and increase the
current. This capacitance should be determined and ambient
measurements repeated with the capacitance in place. There is
also the possibility of resonance conditions with shielded room
filtering, EUT filtering, and powerline inductance. These types
of conditions may need to be investigated if unexpected emission
levels are observed.

Testing outside of a shielded enclosure often must be

performed at night to minimize influences of the ambient. A
prevalent problem with the ambient is that it continuously
changes with time as various emitters are turned on and off and
as amplitudes fluctuate. A useful tool for improving the flow of
testing is to thoroughly analyze the EUT circuitry prior to
testing and identify frequencies where emissions may be expected
to be present.

An option to improve overall measurement accuracy is to make

preliminary measurements inside a shielded enclosure and
accurately determine frequencies where emissions are present.
Testing can be continued outside the shielded enclosure with

A-13
 MIL-STD-462D
APPENDIX

measurements being repeated at the selected frequencies. The

6 dB margin between the ambient and limits must then be observed
only at the selected frequencies.

40.5 (4.5) Ground plane. The EUT shall be installed on a

ground plane that simulates the actual installation. If the
actual installation is unknown or multiple installations are
expected, then a metallic ground plane shall be used. Unless
otherwise specified below, ground planes shall be 2.25 square
meters or larger in area with the smaller side no less than 76
centimeters. When a ground plane is not present in the EUT
installation, the EUT shall be placed on a non-conductive
surface.

DISCUSSION: Generally, the radiated emissions and radiated

susceptibilities of equipment are due to coupling from and to the
interconnecting cables and not via the case of the EUT.
Emissions and susceptibility levels are directly related to the
placement of the cable with respect to the ground plane and to
the electrical conductivity of the ground plane. Thus, the
ground plane plays an important role in obtaining the most
realistic test results.

When the EUT is too large to be installed on a conventional

ground plane on a bench, the actual installation should be
duplicated. For example, a large radar antenna may need to be
installed on a test stand and the test stand bonded to the floor
of the shielded enclosure. Ground planes need to be placed on
the floor of shielded rooms with floor surfaces such as tiles
which are not electrically conductive.

The use of ground planes is also applicable for testing

outside of a shielded enclosure. These ground planes will need
to be referenced to earth as necessary to meet the electrical
safety requirements of the National Electrical Code. Where
possible, these ground planes should be electrically bonded to
other accessible grounded reference surfaces such as the outside
structure of a shielded enclosure.

The minimum dimensions for a ground plane of 2.25 square meter

with 76 centimeters on the smallest side will be adequate only
for setups involving a limited number of EUT enclosures with few
electrical interfaces. The ground plane must be large enough to
allow for the requirements included in paragraph 4.8 on
positioning and arrangement of the EUT and associated cables to
be met.

40.5.1 (4.5.1) Metallic ground plane. When the EUT is

installed on a metallic ground plane, the ground plane shall have
a surface resistance no greater than 0.1 milliohms per square.
The DC resistance between metallic ground planes and the shielded

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enclosure shall be 2.5 milliohms or less. The metallic ground

planes shown in Figures 2 through 5 shall be electrically bonded
to the floor or wall of the basic shielded room structure at
least once every 1 meter. The metallic bond straps shall be
solid and maintain a five-to-one ratio or less in length to
width. Metallic ground planes used outside a shielded enclosure
shall be at least 2 meters by 2 meters and extend at least
0.5 meter beyond the test setup boundary.

DISCUSSION: For the metallic ground plane, a copper ground

plane with a thickness of 0.25 millimeters has been commonly used
and satisfies the surface resistance requirements. Other
metallic materials of the proper size and thickness needed to
achieve the resistivity can be substituted.

For metallic ground planes, the surface resistance can be

calculated by dividing the bulk resistivity by the thickness.
For example, copper has a bulk resistivity of 1.75(10-8)
ohm-meters. For a 0.25 millimeter 2.5(10-4) meters) thick ground
plane as noted above, the surface resistance is
(1.7(10-8))/(2.5(10-4)) = (6.8(10-5)) ohms per square = 0.068
milliohms per square. The requirement is 0.1 milliohms per
square.

40.5.2 (4.5.2) Composite ground plane. When the EUT is

installed on a conductive composite ground plane, the surface
resistivity of the typical installation shall be used. Composite
ground planes shall be electrically bonded to the enclosure with
means suitable to the material.

DISCUSSION: A copper ground plane has typically been used for

all testing in the past. For most instances, this has been
adequate. However, with the increasing use of composites, the
appropriate ground plane will play a bigger role in the test
results. Limited testing on both copper and conductive composite
ground planes has shown some differences in electromagnetic
coupling test results, thus the need exists to duplicate the
actual installation, if possible. In some cases, it may be
necessary to include several ground planes in the same test setup
if different units of the same EUT are installed on different
materials in the installation.

With the numerous different composite materials being used in

installations, it is not possible to specify a general
resistivity value. The typical resistivity of carbon composite
is about 2000 times that of aluminum. The actual resistivity
needs to be obtained from the installation contractor and used
for testing.

40.6 (4.6) Power source impedance. The impedance of power

sources providing input power to the EUT shall be controlled by

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APPENDIX

Line Impedance Stabilization Networks (LISNs) for all

measurements procedures of this document unless otherwise stated
in a particular test method. The LISNs shall be located at the
power source end of the exposed length of power leads specified
in paragraph 4.8.5.2. The LISN circuit shall be in accordance
with the schematic shown in Figure 6. The LISN impedance
characteristics shall be in accordance with Figure 7. The LISN
impedance shall be measured under the following conditions:

a. The impedance shall be measured between the power output

lead on the load side of the LISN and the metal
enclosure of the LISN.

b. The signal output port of the LISN shall be terminated

in fifty ohms.

c. The power input terminal on the power source side of the

LISN shall be unterminated.

The impedance measurement results shall be provided in the EMITR

required by MIL-STD-461

DISCUSSION: The impedance is standardized to represent

expected impedances in actual installations and to ensure
consistent results between different test agencies. Previous
versions of MIL-STD-462 used 10 microfarad feedthrough capacitors
on the power leads. The intent of these devices was to determine
the current generator portion of a Norton current source model.
If the impedance of the interference source were also known, the
interference potential of the source could be analytically
determined for particular circumstances in the installation. A
requirement was never established for measuring the impedance
portion of the source model. More importantly, concerns arose
over the test configuration influencing the design of powerline
filtering. Optimized filters are designed based on knowledge of
both source and load impedances. Significantly different filter
designs will result for the 10 microfarad capacitor loading
versus the impedance loading shown in Figure 7 of the main body.

The particular configuration of the LISN is specified for

several reasons. A number of experiments were performed to
evaluate typical power line impedances present in a shielded room
on various power input types both with and without power line
filters and to assess the possible methods of controlling the
impedance. An approach was considered for the standard to simply
specify an impedance curve from 30 Hz to 100 MHz and to allow the
test agency to meet the impedance using whatever means the agency
found suitable. The experiments showed that there were no
straightforward techniques to maintain desired controls over the
entire frequency range.

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A specific 50 microhenry LISN was selected to maintain a

standardized control on the impedance as low as 10 kHz. Five
microhenry LISNs used commonly in the past provide little control
below 100 kHz. Impedance control below 10 kHz is difficult.
From evaluations of several 50 microhenry LISN configurations,
the one specified demonstrated the best overall performance for
various shielded room filtering variations. Near 10 kHz, the
reactances of the 50 microhenry inductor and 8 microfarad
capacitor cancel and the LISN is effectively a 5 ohm resistive
load across the power line.

Caution needs to be exercised in using the LISN for 400 Hz

power systems. Some existing LISNs may not have components
sufficient to handle the power dissipation requirements. At 115
volts, 400 Hz, the 8 microfarad capacitor and 5 ohm resistor will
pass approximately 2.3 amperes which results in 26.5 watts being
dissipated in the resistor.

40.7 (4.7) General test precautions.

DISCUSSION: The requirements included in paragraph 4.7 cover

important areas related to improving test integrity and safety
that need special attention. There are many other areas where
test difficulties may develop. Some are described here.

It is common for shields to become loose or broken at

connectors on coaxial cables resulting in incorrect readings.
There also are cases where center conductors of coaxial cables
break or separate. Periodic tests should be performed to ensure
cable integrity. Special low loss cables may be required when
testing at higher frequencies.

Caution needs to be exercised when performing emission testing

at frequencies below approximately 10 kHz to avoid ground loops
in the instrumentation which may introduce faulty readings. A
single-point ground often needs to be maintained. It is usually
necessary to use isolation transformers at the measurement
receiver and accessory equipment. The single-point ground is
normally established at the access (feedthrough) panel for the
shielded enclosure. However, if a transducer is being used which
requires an electrical bond to the enclosure (such as the rod
antenna counterpoise), the coaxial cable will need to be routed
through the enclosure access panel without being grounded. Since
the shielded room integrity will then be compromised, a normal
multiple point grounded setup needs to be re-established as low
in frequency as possible.

Rather than routing the coaxial cable through the enclosure

access panel without grounding it to the enclosure, a 50-ohm
video isolation transformer may be connected to the grounded RF
connector at the access panel inside the room. Normal connection

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APPENDIX

of the measuring receiver is made to the grounded connector at

the panel outside the room. This technique effectively breaks
the ground loop without sacrificing the room’s shielding
integrity. The losses of the video isolation transformer must be
accounted for in the measurement data. These devices are
typically useful up to approximately 10 MHz.

If isolation transformers are found to be necessary in

certain setups, problems may exist with items powered by
switching power supplies. A solution is to use transformers
which are rated at approximately five times the current rating of
the item.

Solid state instrumentation power sources have been found to

be susceptible to radiated fields even to the extent of being
shut down. It is best to keep these items outside of the
shielded enclosure.

40.7.1 (4.7.1) Accessory equipment. Accessory equipment

used in conjunction with measurement receivers shall not degrade
measurement integrity.

DISCUSSION: Measurement receivers are generally designed to

meet MIL-STD-461 limits so they do not contaminate the ambient
for emission testing when they are used inside the shielded
enclosure. However, accessory equipment such as computers,
oscilloscopes, plotters, or other instruments used to control the
receiver or monitor its outputs can cause problems. They may
compromise the integrity of the receiver by radiating signals
conducted out of the receiver from improperly treated electrical
interfaces or may produce interference themselves and raise the
ambient. Even passive devices such as headsets have been known
to impact the test results.

It is best to locate all of the test equipment outside of

the shielded enclosure with the obvious exception of the
transducer (antenna or current probe). Proper equipment location
will ensure that the emissions being measured are being generated
in the EUT only and will help ensure that the ambient
requirements of paragraph 4.4 are met. If the equipment must be
used inside the enclosure or if testing is being conducted
outside of an enclosure, the measurement receiver and accessory
equipment should be located as far away from the transducers as
practical to minimize any impact.

40.7.2 (4.7.2) Excess personnel and equipment. The test

area shall be kept free of unnecessary personnel, equipment,
cable racks, and desks. Only the equipment essential to the test
being performed shall be in the test area or enclosure. Only
personnel actively involved in the test shall be permitted in the
enclosure.

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DISCUSSION: Excess personnel and both electronic and

mechanical equipment such as desks or cable racks in the
enclosure can affect the test results. During radiated emission
testing in particular, all nonessential personnel and equipment
need to be removed from the test site. Any object in the
enclosure can significantly influence or introduce standing waves
in the enclosure and thus alter the test results. The
requirement to use RF absorber material will help to mitigate
these effects. However, requirements for the material are not
defined below 80 MHz for practical reasons and standing waves
continue to be a concern.

40.7.3 (4.7.3) Overload precautions. Measurement receivers

and transducers are subject to overload, especially receivers
without preselectors and active transducers. Periodic checks
shall be performed to assure that an overload condition does not
exist. Instrumentation changes shall be implemented to correct
any overload condition.

DISCUSSION: Overloads can easily go unnoticed if there is

not an awareness of the possibility of an overload or active
monitoring for the condition. The usual result is a leveling of
the output indication of the receiver.

Two types of overloads are possible. A narrowband signal

such as a sinusoid can saturate any receiver or active
transducer. Typical procedures for selecting attenuation
settings for measurement receivers place detected voltages
corresponding to MIL-STD-461 emission limits well within the
dynamic range of the receiver. Saturation problems for
narrowband type signals will normally only appear for a properly
configured receiver if emissions are significantly above the
limits. Saturation can occur more readily when receivers are
used to monitor susceptibility signals due to the larger voltages
involved.

Overload from impulsive type signals with broad frequency

content can be much more deceptive. This condition is most
likely to occur with devices without a tuneable bandpass feature
in the first stage of the signal input. Examples are
preamplified rod antennas and receivers without preselectors
(primarily certain spectrum analyzers). The input circuitry is
exposed to energy over a large portion of the frequency spectrum.
Preselectors include a tuneable tracking filter which bandwidth
limits the energy applied to the receiver front end circuitry.

Measurement receiver overload to both narrowband and

impulsive type signals can be evaluated by applying 10 dB
additional attenuation in the first stage of the receiver (before
mixer circuitry) or external to the receiver. If overload is not
present, the observed output will uniformly decrease by 10 dB.

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Overload conditions for active antennas are normally

published as part of the literature supplied with the antenna.
For narrowband signals, the indicated level in the data can be
reviewed with respect to the literature to evaluate overload.
Levels are also published for impulsive type signals; however,
these levels are not very useful since they usually assume that a
flat field exists across the useable range of the antenna. In
reality, the impulsive field will vary significantly with
frequency and the antenna circuitry sees the integration of the
spectral content of this field over its bandpass. The primary
active antenna used is an active rod antenna. Overload can be
evaluated by collapsing the rod and observing the change in
indication. If overload is not present, the indicated level
should drop approximately 8 dB. The actual change for any
particular manufacturer’s product will depend on the telescoping
design and can be determined by radiating a signal to the antenna
which is within its linear range.

40.7.4 (4.7.4) RF hazards. Some tests in this standard

will result in electromagnetic fields which are potentially
dangerous to personnel. The permissible exposure levels in ANSI
C95.1 shall not be exceeded in areas where personnel are present.
Safety procedures and devices shall be used to prevent accidental
exposure of personnel to RF hazards.

DISCUSSION: During some radiated susceptibility and radiated

emission testing, RS103, RS105 and RE103 in particular, fields
may exceed the permissible exposure levels in ANSI C95.1. During
these tests, precautions must be implemented to avoid inadvertent
exposure of personnel. Monitoring of the EUT during testing may
require special techniques such as remotely connected displays
external to the enclosure or closed circuit television to
adequately protect personnel.

40.7.5 (4.7.5) Shock hazard. Some of the tests require

potentially hazardous voltages to be present. Extreme caution
must be taken by all personnel to assure that all safety
precautions are observed.

DISCUSSION: A safety plan and training of test personnel are

normally required to assure that accidents are minimized. Test
equipment manufacturers’ precautions need to be followed, if
specified. If these are not available, the test laboratory
should establish adequate safety precautions and train all test
personnel. Special attention should be observed for Method CS109
since electronics enclosures are intentionally isolated from the
ground plane for test purposes.

40.7.6 (4.7.6) Federal Communication Commission (FCC)

restrictions. Some of the tests require high level signals to be
generated that could interfere with normal FCC approved frequency

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assignments. All such testing should be conducted in a shielded

enclosure. Some open site testing may be feasible if prior FCC
coordination is obtained.

DISCUSSION: Radiated susceptibility RS103 testing and

possibly other tests will produce signals above FCC
authorizations. This situation is one of the reasons that
shielded enclosures are usually required for MIL-STD-462 testing.
In some rare instances, the FCC may permit levels higher than
normal if prior coordination is obtained.

40.8 (4.8) EUT test configurations. The EUT shall be

configured as shown in the general test setups of Figures 1
through 5 as applicable. These setups shall be maintained during
all testing unless other direction is given for a particular test
method.

DISCUSSION: Emphasis is placed on "maintaining" the

specified setup for all testing unless a particular test method
directs otherwise. Confusion has resulted from previous versions
of the standard regarding consistency of setups from test method
to test method in areas such as lead lengths and placement of
10 uF capacitors on power leads. In this version of the
standard, any changes from the general test setup are
specifically stated in the individual test method.

40.8.1 (4.8.1) Bonding of EUT. Only the provisions

included in the design of the EUT shall be used to bond units
such as equipment case and mounting bases together, or to the
ground plane. When bonding straps are required to complete the
test setup, they shall be identical to those specified in the
installation drawings.

DISCUSSION: Electrical bonding provisions for equipment are

an important aspect of platform installation design. Adequacy of
bonding is usually one of the first areas reviewed when platform
problems develop. Electrical bonding controls common mode
voltages that develop between the equipment enclosures and the
ground plane. Voltages potentially affecting the equipment will
appear across the bonding interface when RF stresses are applied
during susceptibility testing. Voltages will also develop due to
internal circuit operation and will contribute to radiated
emission profiles. Therefore, it is important that the test
setup use actual bonding provisions so that test results are
representative of the intended installation.

40.8.2 (4.8.2) Shock and vibration isolators. EUTs shall

be secured to mounting bases having shock or vibration isolators
if such mounting bases are used in the installation. The bonding
straps furnished with the mounting base shall be connected to the

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ground plane. When mounting bases do not have bonding straps,

bonding straps shall not be used in the test setup.

DISCUSSION: Including shock and vibration isolators in the

setup when they represent the platform installation is important.
The discussion above for paragraph 4.8.1 is also applicable to
shock and vibration isolators; however, the potential effect on
test results is even greater. Hard mounting of the equipment
enclosures to the ground plane can produce a low impedance path
across the bonding interface over most of the frequency range of
interest. The bonding straps associated with isolators will
typically represent significant impedances at frequencies as low
as tens of kilohertz. The common mode voltages associated with
these impedances will generally be greater than the hard mounted
situation. Therefore, the influence on test results can be
substantial.

40.8.3 (4.8.3) Wire grounds. When external terminals,

connector pins, or equipment grounding conductors in power cables
are available for ground connections and are used in the actual
installation, they shall be connected to the ground plane after a
2 meter exposed length (see 4.8.5). Shorter lengths shall be
used if they are specified in the installation instructions.

DISCUSSION: Wire grounds used in equipment enclosures have

been the source of problems during EMI testing. Since they are
connected to the equipment enclosure, they would be expected to
be at a very low potential with respect to the ground plane and a
non-contributor to test results. However, the wire lengths
within enclosures are often sufficiently long that coupling to
them results from noisy circuits. Also, the wire grounds can
conduct induced signals from external sources and reradiate
within the equipment enclosure. Therefore, they must be treated
similarly to other wiring.

40.8.4 (4.8.4) Orientation of EUTs. EUTs shall be oriented

such that surfaces which produce maximum radiated emissions and
respond most readily to radiated signals face the measurement
antennas. Bench mounted EUTs shall be located 10 +2 centimeters
from the front edge of the ground plane subject to allowances for
providing adequate room for cable arrangement as specified below.

DISCUSSION: Determination of appropriate surfaces is usually

straightforward. Seams on enclosures which have metal-to-metal
contact or contain EMI gaskets rarely contribute and should be
considered low priority items. Prime candidates are displays
such as video screens, ventilation openings, and cable
penetrations. In some cases, it may be necessary to probe the
surfaces with a sensor and measurement receiver to decide on EUT
orientation.

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Previous versions of this standard specifically required

probing with a loop antenna to determine localized areas
producing maximum emissions or susceptibility for radiated
electric field testing. The test antennas were to be placed one
meter from the identified areas. The requirement was not
included in this version of MIL-STD-462 due to difficulties in
applying the requirement and the result that probing was often
not performed. Probing implies both scanning in frequency and
physical movement of the probe. These two actions cannot be
performed in a manner to cover all physical locations at all
frequencies. A complete frequency scan can be performed at
particular probe locations and movement of the probe over the
entire test setup can be performed at particular frequencies.
The detailed requirements on the use of multiple antenna
positions and specific requirements on the placement of the
antennas in test methods RE102 and RS103 minimize concerns with
the need to probe.

40.8.5 (4.8.5) Construction and arrangement of EUT cables.

Electrical cable assemblies shall simulate actual installation
and usage. Shielded cables or shielded leads (including power
lead and wire grounds) within cables shall be used only if they
have been specified in installation drawings. Cables shall be
checked against installation requirements to verify proper
construction techniques such as use of twisted pairs, shielding,
and shield terminations. Details on the cable construction used
for testing shall be included in the EMITP.

DISCUSSION: For most EUTs, electrical interface requirements

are covered in interface control or similar documents.
Coordination between equipment manufacturers and system
integration organizations is necessary to ensure a compatible
installation from both functional and electromagnetic
interference standpoints. For general purpose EUTs, which may be
used in many different installations, either the equipment
specifications cover the interface requirements or the
manufacturers publish recommendations in the documentation
associated with the equipment.

Equipment manufacturers sometimes contend that failures

during EMI testing are not due to their equipment and can be
cured simply by placing overall shields on the interface cabling.
This concept is unacceptable. High level emissions are often
caused by electronic circuits within EUT enclosures coupling onto
cables simulating the installation which interface with the EUT.
Overall shielding of the cabling is certainly permissible if it
is present in the installation. However, the use of overall
shielding which is not representative of the installation would
result in test data which is useless. Also, overall shielding of
cabling in some installations is not a feasible option due to
weight and maintenance penalties. The presence of platform

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APPENDIX

structure between cabling and antennas on a platform is not an

acceptable reason for using overall shields on cables for testing
in accordance with this standard. The presence of some platform
shielding is a basic assumption.

There may be instances when published interface information

is not available. In this case, overall shielding is not to be
used. Individual circuits are to be treated as they typically
would for that type of interface with shielding not used in
questionable cases.

For some testing performed in the past using bulk cable

drive techniques, overall cable shields were routinely removed
and the injected signal was applied to the core wiring within the
shield. The intent of this standard is to test cables as they
are configured in the installation. If the cable uses an overall
shield, the test signal is applied to the overall shielded cable.
If the procuring agency desires that the test be performed on the
core wiring, specific wording needs to be included in contractual
documentation.

40.8.5.1 (4.8.5.1) Interconnecting leads and cables.

Individual leads shall be grouped into cables in the same manner
as in the actual installation. Total interconnecting cable
lengths in the setup shall be the same as in the actual platform
installation. If the cable is longer than 10 meters, at least
10 meters shall be included. When cable lengths are not
specified for the installation, cables shall be sufficiently long
to satisfy the conditions specified below. At least 2 meters
(except for cables which are shorter in the actual installation)
of each interconnecting cable shall be run parallel to the front
boundary of the setup. Remaining cable lengths shall be routed
to the back of the setup and shall be placed in a zig-zagged
arrangement. When the setup includes more than one cable,
individual cables shall be separated by 2 centimeters measured
from their outer circumference. For bench top setups using
ground planes, the cable closest to the front boundary shall be
placed 10 centimeters from the front edge of the ground plane.
All cables shall be supported 5 centimeters above the ground
plane.

DISCUSSION: Actual lengths of cables used in installations

are necessary for several reasons. At frequencies below
resonance, coupling is generally proportional to cable length.
Resonance conditions will be representative of the actual
installation. Also, distortion and attenuation of intentional
signals due strictly to cable characteristics will be present and
potential susceptibility of interface circuits to induced signals
will therefore be similar to the actual installation.

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Zig-zagging of long cables is accomplished by first placing

a length of cable in an open area and then reversing the
direction of the cable run by 180 degrees each time a change of
direction is required. Each subsequent segment is farther from
the first. Individual segments of the cable are parallel and
should be kept 2 centimeters apart. This arrangement is
sometimes called a serpentine pattern. The zig-zagging of long
cables rather than coiling is to control excess inductance. A
2 centimeter spacing between cables is required to expose all
cabling to the test antennas and limit coupling of signals
between cables. The 10 centimeter dimension for cables from the
front edge of the ground plane ensures that there is sufficient
ground plane surface below the first cable to be effective. The
5 centimeter standoffs standardize loop areas available for
coupling and capacitance to the ground plane. The standoffs
represent routing and clamping of cables in actual installations
a fixed distance from structure.

In some military applications, there can be over 2000 cables

associated with a subsystem. In most cases where large number of
cables are involved, there will be many identical cable
interfaces connected to identical circuitry. Testing of every
cable interface is not necessary in this situation. The EMITP
should document instances where these circumstances exist and
should propose which cables are to be included in the setup and
to be tested.

40.8.5.2 (4.8.5.2) Input power leads. Two meters of input

power leads (including returns) shall be routed parallel to the
front edge of the setup in the same manner as the interconnecting
leads. The power leads shall be connected to the LISNs (see
4.6). Power leads that are part of an interconnecting cable
shall be separated out at the EUT connector and routed to the
LISNs. After the 2 meter exposed length, the power leads shall
be terminated at the LISNs in as short a distance as possible.
The total length of power lead from the EUT electrical connector
to the LISNs shall not exceed 2.5 meters. All power leads shall
be supported 5 centimeter above the ground plane. If the power
leads are twisted in the actual installation, they shall be
twisted up to the LISNs.

DISCUSSION: Appropriate power lead length is a trade-off

between ensuring sufficient length for efficient coupling of
radiated signals and maintaining the impedance of the LISNs. To
keep a constant setup, it is undesirable to change the power lead
length for different test methods. Requiring a 2 meter exposed
length is consistent with treatment of interconnecting leads for
radiated concerns. Wiring inductance 5 centimeter from a ground
plane is approximately 1 microhenry/meter. At 1 MHz this
inductance has an impedance of approximately 13 ohms which is
significant with respect to the LISN requirement.

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The LISN requirement standardizes impedance for power leads.

While signal and control circuits are usually terminated in
specified impedances, power circuit impedances are not usually
well defined. The LISN requirement applies to all input prime
power leads. The LISN requirement does not apply to output power
leads. These leads should be terminated after the 2 meter
exposed length in a load representing worst-case conditions.
This load would normally draw the maximum current allowed for the
power source.

The construction of the power cable between the EUT and the
LISNs must be in accordance with the requirements of paragraph
4.8.5. For example, if a twisted triplet is used to distribute
three phase delta power in the actual installation, the same
construction should be used in the test setup. The normal
construction must be interrupted over a sufficient length to
permit connection to the LISNs.

40.8.6 (4.8.6) Electrical and mechanical interfaces. All

electrical input and output interfaces shall be terminated with
either the actual equipment from the platform installation or
loads which simulate the electrical properties (impedance,
grounding, balance, and so forth) present in the actual
installation. Signal inputs shall be applied to all applicable
electrical interfaces to exercise EUT circuitry. EUTs with
mechanical outputs shall be suitably loaded. When variable
electrical or mechanical loading is present in the actual
installation, testing shall be performed under expected worst
case conditions. When active electrical loading (such as a test
set) is used, precautions shall be taken to ensure the active
load meets the ambient requirements of paragraph 4.4 when
connected to the setup, and that the active load does not respond
to susceptibility signals. Antenna ports on the EUT shall be
terminated with shielded, matched loads.

DISCUSSION: The application of signals to exercise the

electrical interface is necessary to effectively evaluate
performance. Most electronic subsystems on platforms are highly
integrated with large amounts of digital and analog data being
transferred between equipment. The use of actual platform
equipment for the interfacing eliminates concerns regarding
proper simulation of the interface. The interfaces must function
properly in the presence of induced levels from susceptibility
signals. Required isolation may be obtained by filtering the
interface leads at the active load and either shielding the load
or placing it outside of the shielded enclosure. The filtering
should be selected to minimize the influence on the interface
electrical properties specified above. For proper simulation,
filtering at the loads should be outside the necessary bandwidth
of the interface circuitry.

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Antenna ports are terminated in loads for general setup

conditions. Specific test methods address electromagnetic
characteristics of antenna ports and required modifications to
the test setup.

40.9 (4.9) Operation of EUT. During emission measurements,

the EUT shall be placed in an operating mode which produces
maximum emissions. During susceptibility testing, the EUT shall
be placed in its most susceptible operating mode. For EUTs with
several available modes (including software controlled
operational modes), a sufficient number of modes shall be tested
for emissions and susceptibility such that all circuitry is
evaluated.

DISCUSSION: The particular modes selected may vary for

different test methods. Considerations for maximum emissions
include conditions which cause the EUT to draw maximum prime
power current, result in greatest activity in interface circuit
operation, and generate the largest current drain on internal
digital clock signals. Settings for a radar could be adjusted
such that an output waveform results which has the highest
available average power. Data bus interfaces could be queried
frequently to cause constant bus traffic flow. Any modes of the
EUT which are considered mission critical in the installation
should be evaluated during susceptibility testing.

A primary consideration for maximum susceptibility is

placing the EUT in its most sensitive state for reception of
intentional signals (maximum gain). An imaging sensor would
normally be evaluated with a scene meeting the most stringent
specifications for the sensor. RF receivers are normally
evaluated using an input signal at the minimum signal to noise
specification of the receiver. An additional consideration is
ensuring that all electrical interfaces which intentionally
receive data are exercised frequently to monitor for potential
responses.

40.9.1 (4.9.1) Operating frequencies for tunable RF

equipment. Measurements shall be performed with the EUT tuned to
not less than three frequencies within each tuning band, tuning
unit, or range of fixed channels, consisting of one mid-band
frequency and a frequency within +5 percent from each end of each
band or range of channels.

DISCUSSION: Tuned circuits and frequency synthesis

circuitry inside RF equipment typically vary in characteristics
such as response, rejection, and spectral content of emissions as
they are set to different frequencies. Several test frequencies
are required simply to obtain a sampling of the performance of
the EUT across its operating range.

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40.9.2 (4.9.2) Operating frequencies for spread spectrum

equipment. Operating frequency requirements for two major types
of spread spectrum equipment shall be as follows:

a. Frequency hopping. Measurements shall be performed with

the EUT utilizing a hop set which contains 30% of the
total possible frequencies. The hop set shall be
divided equally into three segments at the low, mid, and
high end of the EUT’s operational frequency range.

b. Direct sequence. Measurements shall be performed with

the EUT processing data at its highest possible data
transfer rate.

DISCUSSION: During testing it is necessary to operate

equipments at levels that they will experience during normal
field operations to allow for a realistic representation of the
emission profile of the EUT during radiated and conducted testing
and to provide realistic loading and simulation of the EUT during
radiated and conducted susceptibility testing.

Frequency hopping: Utilization of a hopset which is

distributed across the entire operational spectrum of the EUT
will help assure that internal circuitry dependent on the exact
EUT transmit frequency being used is active intermittently during
processing of the entire pseudo random stream. The fast
operating times of hopping receivers/transmitters versus the
allowable measurement times of the measurement receivers being
used (paragraph 4.10.4) will allow a representative EUT emission
signature to be captured.

Direct sequence: Requiring the utilization of the highest

data transfer rate used in actual operation of the EUT should
provide a representative worst-case radiated and conducted
emission profile. Internal circuitry will operate at its highest
processing rate when integrating the data entering the
transmitter, and then resolving (disintegrating) the data back
once again on the receiver end. Additionally, the data rate will
need to be an area of concentration during all susceptibility
testing.

40.9.3 (4.9.3) Susceptibility monitoring. The EUT shall be

monitored during susceptibility testing for indications of
degradation or malfunction. This monitoring is normally
accomplished through the use of built-in-test (BIT), visual
displays, aural outputs, and other measurements of signal outputs
and interfaces. Monitoring of EUT performance through
installation of special circuitry in the EUT is permissible;
however, these modifications shall not influence test results.

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DISCUSSION: Most EUTs can be adequately monitored through

normal visual and aural outputs, self diagnostics, and electrical
interfaces. The addition of special circuitry for monitoring can
present questions related to its influence on the validity of the
test results and may serve as an entry or exit point for
electromagnetic energy.

The monitoring procedure needs to be specified in the EMITP

and needs to include allowances for possible weaknesses in the
monitoring process to assure the highest probability of finding
regions of susceptibility.

40.10 (4.10) Use of measuring equipment. Measuring

equipment shall be as specified in the individual test methods of
this standard. Any frequency selective measurement receiver may
be used for performing the testing described in this standard
provided that the receiver characteristics (that is, sensitivity,
selection of bandwidths, detector functions, dynamic range, and
frequency of operation) meet the constraints specified in this
standard and are sufficient to demonstrate compliance with the
applicable limits of MIL-STD-461. Typical instrumentation
characteristics may be found in ANSI C63.2

DISCUSSION: Questions frequently arise concerning the

acceptability for use of measurement receivers other than
instruments that are specifically designated "field intensity
meters" or "EMI receivers". Most questions are directed toward
the use of spectrum analyzers. These instruments are generally
acceptable for use. However, depending on the type, they can
present difficulties which are not usually encountered with the
other receivers. Sensitivity may not be adequate in some
frequency bands requiring that a low noise preamplifier be
inserted before the analyzer input. Impulse type signals from
the EUT with broad spectral content may overload the basic
receiver or preamplifier. The precautions of paragraph 4.7.3
must be observed. Both of these concerns can usually be
adequately addressed by the use of a preselector with the
analyzer. These devices typically consist of a tunable filter
which tracks the analyzer followed by a preamplifier.

ANSI C63.2 represents a coordinated position from industry

on required characteristics of instrumentation receivers. This
document can be consulted when assessing the performance of a
particular receiver.

Many of the test methods require non-specialized

instrumentation which is used for many other purposes. The test
facility is responsible for selecting instrumentation which has
characteristics capable of satisfying the requirements of a
particular test method.

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Current probes used for EMI testing are more specialized

instrumentation. These devices are current transformers with the
circuit under test forming a single turn primary. They are
designed to be terminated in 50 ohms. Current probes are
calibrated using transfer impedance which is the ratio of the
voltage output of the probe across 50 ohms to the current through
the probe. Probes with higher transfer impedance provide better
sensitivity. However, these probes also result in more series
impedance added to the circuit with a greater potential to affect
the electrical current level. The series impedance added by the
probe is the transfer impedance divided by the number of turns in
the secondary winding on the probe. Typical transfer impedances
are 5 ohms or less. Typical added series impedance is 1 ohm or
less.

40.10.1 (4.10.1) Detector. A peak detector shall be used

for all frequency domain emission and susceptibility
measurements. This device detects the peak value of the
modulation envelope in the receiver bandpass. Measurement
receivers are calibrated in terms of an equivalent root mean
square (RMS) value of a sine wave that produces the same peak
value. When other measurement devices such as oscilloscopes,
non-selective voltmeters, or broadband field strength sensors are
used for susceptibility testing, correction factors shall be
applied for test signals to adjust the reading to equivalent RMS
values under the peak of the modulation envelope.

DISCUSSION: The function of the peak detector and the

meaning of the output indication on the measurement receiver are
often confusing. Although there may appear to be an inherent
discrepancy in the use of the terms "peak" and "RMS" together,
there is no contradiction. All detector functions (that is peak,
carrier, field intensity, and quasi-peak) process the envelope of
the signal present in the receiver intermediate frequency (IF)
section. All outputs are calibrated in terms of an equivalent
RMS value. For a sine wave input to the receiver, the signal
envelope in the IF section is a DC level and all detectors
produce the same indicated RMS output. Calibration in terms of
RMS is necessary for consistency. Signal sources are calibrated
in terms of RMS. If a 0 dBm (107 dBµV) unmodulated signal is
applied to the receiver, the receiver must indicate 0 dBm
(107 dBµV).

If there is modulation present on the signal applied to the

receiver, the detectors respond differently. The IF section of
the receiver sees the portion of the applied signal within the
bandwidth limits of the IF. The peak detector senses the largest
level of the signal envelope in the IF and displays an output
equal to the RMS value of a sine wave with the same peak. The
specification of a peak detector ensures that the worst case
condition for emission data is obtained. A carrier detector

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averages the modulation envelope based on selected charge and

discharge time constants.

Figure A-1 shows the peak detector output for several

modulation waveforms. An item of interest is that for a square
wave modulated signal, which can be considered a pulse type
modulation, the receiver can be considered to be displaying the
RMS value of the pulse when it is on. Pulsed signals are often
specified in terms of peak power. The RMS value of a signal is
derived from the concept of power, and a receiver using a peak
detector correctly displays the peak power.

IF SIGNAL EQUIVALENT SINE WAVE, SAME PEAK

A A

B B

C C

RECEIVER OUTPUT INDICATION WILL BE A B C

, , , RESPECTIVELY
2 2 2

FIGURE A-1. Peak detector response.

All frequency domain measurements are standardized with

respect to the response that a measurement receiver using a peak
detector would provide. Therefore, when instrumentation is used
which does not use peak detection, correction factors must be
applied for certain signals. For an oscilloscope, the maximum

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APPENDIX

amplitude of the modulated sine wave measured from the DC level

is divided by 1.414 (square root of 2) to determine the RMS value
at the peak of the modulation envelope.

Correction factors for other devices are determined by

evaluating the response of the instrumentation to signals with
the same peak level with and without modulation. For example, a
correction factor for a broadband field sensor can be determined
as follows. Place the sensor in an unmodulated field and note
the reading. Apply the required modulation to the field ensuring
that the peak value of the field is the same as the unmodulated
field. For pulse type modulation, most signal sources will
output the same peak value when modulation is applied. Amplitude
modulation increases the peak amplitude of the signal and caution
must be observed. Note the new reading. The correction factor
is simply the reading with the unmodulated field divided by the
reading with the modulated field. If the meter read
10 volts/meter without modulation and 5 volts/meter with
modulation, the correction factor is 2. The evaluation should be
tried at several frequencies and levels to ensure that a
consistent value is obtained. When subsequently using the sensor
for measurements with the evaluated modulation, the indicated
reading is multiplied by the correction factor to obtain the
correct reading for peak detection.

40.10.2 (4.10.2) Computer-controlled receivers. A

description of the operations being directed by software for
computer-controlled receivers shall be included in the EMITP
required by MIL-STD-461. Verification techniques used to
demonstrate proper performance of the software shall also be
included.

DISCUSSION: Computer software obviously provides excellent

opportunities for automating testing. However, it also can lead
to errors in testing if not properly used or if incorrect code is
present. It is essential that users of the software understand
the functions it is executing, know how to modify parameters
(such as transducer or sweep variables) as necessary, and perform
sanity checks to ensure that the overall system performs as
expected.

40.10.3 (4.10.3) Emission testing.

40.10.3.1 (4.10.3.1) Bandwidths. The measurement receiver

bandwidths listed in Table II shall be used for emission testing.
These bandwidths are specified at the 6 dB down points for the
overall selectivity curve of the receivers. Video filtering
shall not be used to bandwidth limit the receiver response. If a
controlled video bandwidth is available on the measurement
receiver, it shall be set to its greatest value. Larger
bandwidths may be used; however, they may result in higher

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measured emission levels. NO BANDWIDTH CORRECTION FACTORS SHALL

BE APPLIED TO TEST DATA DUE TO THE USE OF LARGER BANDWIDTHS.

TABLE II. Bandwidth and Measurement Time.

Frequency Range 6 dB Dwell Minimum Measurement Time

Bandwidth Time Analog Measurement
Receiver
30 Hz - 1 kHz 10 Hz 0.15 sec 0.015 sec/Hz
1 kHz - 10 kHz 100 Hz 0.015 sec 0.15 sec/kHz
10 kHz - 250 kHz 1 kHz 0.015 sec 0.015 sec/kHz
250 kHz - 30 MHz 10 kHz 0.015 sec 1.5 sec/MHz
30 MHz - 1 GHz 100 kHz 0.015 sec 0.15 sec/MHz
Above 1 GHz 1 MHz 0.015 sec 15 sec/GHz

DISCUSSION: The bandwidths specified in Table II are

consistent with the recommended available bandwidths and the
bandwidth specifications technique for receivers contained in
ANSI C63.2. Existing receivers have bandwidths specified in a
number of different ways. Some are given in terms of 3 dB down
points. The 6 dB bandwidths are usually about 40% greater than
the 3 dB values. Impulse bandwidths are usually very similar to
the 6 dB bandwidths. For gaussian shaped bandpasses, the actual
value is 6.8 dB.

In order not to restrict the use of presently available

receivers which do not have the specified bandwidths, larger
bandwidths are permitted. The use of larger bandwidths can
produce higher detected levels for wide bandwidth signals. The
prohibition against the use of correction factors is included to
avoid any attempts to classify signals. This version of the
standard has eliminated the concept of classification of
emissions as broadband or narrowband in favor of fixed bandwidths
and single limits specified in MIL-STD-461. Emission
classification was a controversial area often poorly understood
and handled inconsistently among different facilities.

40.10.3.2 (4.10.3.2) Emission identification. All

emissions regardless of characteristics shall be measured with
the measurement receiver bandwidths specified in Table II and
compared against the limits in MIL-STD-461. Identification of
emissions with regard to narrowband or broadband categorization
is not applicable.

DISCUSSION: Requirements for specific bandwidths and the use

of single limits are intended to resolve a number of problems.

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Previous versions of this standard had no controls on required

bandwidths and MIL-STD-461 provided both narrowband and broadband
limits over much of the frequency range of most emission
requirements. The significance of the particular bandwidths
chosen for use by a test facility were addressed by
classification of the appearance of the emissions with respect to
the chosen bandwidths. Emissions considered to be broadband had
to be normalized to equivalent levels in a 1 MHz bandwidth. The
bandwidths and classification techniques used by various
facilities were very inconsistent and resulted in a lack of
standardization. The basic issue of emission classification was
often poorly understood and implemented. Requiring specific
bandwidths with a single limit eliminates any need to classify
emissions.

An additional problem is that emission profiles from modern

electronics are often quite complex. Some emission signatures
have frequency ranges where the emissions exhibit white noise
characteristics. Normalization to a 1 MHz bandwidth using
spectral amplitude assumptions based on impulse noise
characteristics is not technically correct. Requiring specific
bandwidths eliminates normalization and this discrepancy.

40.10.3.3 (4.10.3.3) Frequency scanning. For emission

measurements, the entire frequency range for each applicable test
shall be scanned. Minimum measurement time for analog
measurement receivers during emission testing shall be as
specified in Table II. Synthesized measurement receivers shall
step in one-half bandwidth increments or less, and the
measurement dwell time shall be as specified in Table II.

DISCUSSION: For each emission test, the entire frequency

range as specified in the applicable portion of MIL-STD-461 must
be scanned to ensure that all emissions are measured.

Continuous frequency coverage is required for emission

testing. Testing at discrete frequencies is not acceptable
unless otherwise stated in a particular test method. The minimum
scan times listed in Table II are based on two considerations.
The first consideration is the response time of a particular
bandwidth to an applied signal. This time is 1/(filter
bandwidth). The second consideration is the potential rates
(that is modulation, cycling, and processing) at which
electronics operate and the need to detect the worst case
emission amplitude. Emission profiles usually vary with time.
Some signals are present only at certain intervals and others
vary in amplitude. For example, signals commonly present in
emission profiles are harmonics of microprocessor clocks. These
harmonics are very stable in frequency; however, their amplitude
tends to change as various circuitry is exercised and current
distribution changes.

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The first entry in the table for analog measurement

receivers of 0.015 sec/Hz for a bandwidth of 10 Hz is the only
one limited by the response time of the measurement receiver
bandpass. The response time is 1/bandwidth = 1/10 Hz = 0.1
seconds. Therefore, as the receiver tunes, the receiver bandpass
must include any particular frequency for 0.1 seconds implying
that the minimum scan time = 0.1 seconds/10 Hz = 0.01 seconds/Hz.
The value in the table has been increased to 0.015 seconds/Hz to
ensure adequate time. This increase by a multiplication factor
of 1.5 results in the analog receiver having a frequency in its
bandpass for 0.15 seconds as it scans. This value is the dwell
time specified in the table for synthesized receivers for 10 Hz
bandwidths. Since synthesized receivers are required to step in
one-half bandwidth increments or less and dwell for 0.15 seconds,
test time for synthesized receivers will be greater than analog
receivers.

The measurement times for other table entries are controlled

by the requirement that the receiver bandpass include any
specific frequency for a minimum of 15 milliseconds (dwell time
in table), which is associated with a potential rate of variation
of approximately 60 Hz. As the receiver tunes, the receiver
bandpass is required to include any particular frequency for the
15 milliseconds. For the fourth entry in the table of 1.5
seconds/MHz for a 10 kHz bandwidth, the minimum measurement time
is 0.015 seconds/0.01 MHz = 1.5 seconds/MHz. A calculation based
on the response time of the receiver would yield a response time
of 1/bandwidth = 1/10 kHz = 0.0001 seconds and a minimum
measurement time of 0.0001 seconds/0.01 MHz = 0.01 seconds/MHz.
The longer measurement time of 1.5 seconds/MHz is specified in
the table. If the specified measurement times are not adequate
to capture the maximum amplitude of the EUT emissions, longer
measurement times should be implemented.

Caution must be observed in applying the measurement times.

The specified parameters are not directly available on
measurement receiver controls and must be interpreted for each
particular receiver. Also, the specified measurement times may
be too fast for some data gathering devices such as real-time X-Y
recording. Measurement receiver peak hold times must be
sufficiently long for the mechanical pen drive on X-Y recorders
to reach the detected peak value. In addition, the scan speed
must be sufficiently slow to allow the detector to discharge
after the signal is detuned so that the frequency resolution
requirements of paragraph 4.10.6 are satisfied.

40.10.3.4 (4.10.3.4) Emission data presentation. Amplitude

versus frequency profiles of emission data shall be automatically
and continuously plotted. The applicable limit shall be
displayed on the plot. Manually gathered data is not acceptable
except for plot verification. The plotted data for emission

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measurements shall provide a minimum frequency resolution of 1%

or twice the measurement receiver bandwidth, whichever is less
stringent, and a minimum amplitude resolution of 1 dB. The above
resolution requirements shall be maintained in the reported
results of the EMITR.

DISCUSSION: Previous versions of this standard permitted

data to be taken at the three frequencies per octave for the
highest amplitude emissions. This approach is no longer
acceptable. Continuous displays of amplitude versus frequency
are required. This information can be generated in a number of
ways. The data can be plotted real-time as the receiver scans.
The data can be stored in computer memory and later dumped to a
plotter. Photographs of video displays are acceptable; however,
it is generally more difficult to meet resolution requirements
and to reproduce data in this form for submittal in an EMITR.

Placement of limits can be done in several ways. Data may

be displayed with respect to actual MIL-STD-461 limit dimensions
(such as dBµV/m) with transducer, attenuation and cable loss
corrections made to the data. An alternative is to plot the raw
data in dBµv (or dBm) and convert the limit to equivalent dBµv
(or dBm) dimensions using the correction factors. This second
technique has the advantage of displaying the proper use of the
correction factors. Since both the emission level and the
required limit are known, a second party can verify proper
placement. Since the actual level of the raw data is not
available for the first case, this verification is not possible.

An example of adequate frequency and amplitude resolution is

shown in Figure A-2. 1% frequency resolution means that two
sinusoidal signals of the same amplitude separated by 1% of the
tuned frequency are resolved in the output display so that they
both can be seen. As shown in the figure, 1% of the measurement
frequency of 5.1 MHz is 0.051 MHz and a second signal at
5.151 MHz (1 dB different in amplitude on the graph) is easily
resolved in the display. The "2 times the measurement receiver
bandwidth" criteria means that two sinusoidal signals of the same
amplitude separated by twice the measurement receiver bandwidth
are resolved. For the example shown in Figure A-2, the bandwidth
is 0.01 MHz and 2 times this value is 0.02 MHz. Therefore, the
1% criterion is less stringent and is applicable. 1 dB amplitude
resolution means that the amplitude of the displayed signal can
be read within 1 dB. As shown in the figure, the reviewer can
determine whether the signal amplitude is 60 dBµV or 61 dBµV.

The difference between resolution and accuracy is sometimes

confusing. Paragraph 4.1.1 of the standard requires 3 dB
measurement system accuracy for amplitude while paragraph 4.10.6
of the standard requires 1 dB amplitude resolution. Accuracy is
an indication how precisely a value needs to be known while

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resolution is an indication of the ability to discriminate

between two values. A useful analogy is reading time from a
watch. A watch typically indicates the time within one second
(resolution) but may be 30 seconds different than the absolute
correct time (accuracy).

EMISSION LEVEL (dBuV)

70

60
5.1 MHz
61 dBuV 5.151 MHz
60 dBuV
50

40

30

20

10
4 5 6 7 8
FREQUENCY (MHz)

FIGURE A-2. Example of data presentation resolution.

40.10.4 (4.10.4) Susceptibility testing.

40.10.4.1 (4.10.4.1) Frequency scanning. For

susceptibility measurements, the entire frequency range of each
applicable test shall be scanned. For swept frequency
susceptibility testing, frequency scan rates and frequency step
sizes of signal sources shall not exceed the values listed in
Table III. The rates and step sizes are specified in terms of a
multiplier of the tuned frequency (fo) of the signal source.
Analog scans refer to signal sources which are continuously
tuned. Stepped scans refer to signal sources which are
sequentially tuned to discrete frequencies. Stepped scans shall
dwell at each tuned frequency for a minimum of 1 second. Scan

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rates and step sizes shall be decreased when necessary to permit

observation of a response.

DISCUSSION: For any susceptibility test performed in the

frequency domain, the entire frequency range as specified in MIL-
STD-461 must be scanned to ensure that all potentially
susceptible frequencies are evaluated.

The scan rates and step sizes in Table III are structured to
allow for a continuous change in value with frequency for
flexibility. Computerized test systems could be programmed to
change values very frequently. A more likely application is to
block off selected bands for scanning and to base selections of
scan rate or step size on the lowest frequency. For example, if
1 - 2 GHz were selected, the maximum scan rate would be (0.002 X
1 GHz)/sec which equals 2 MHz/sec and the maximum step size would
be 0.001 X 1 GHz which equals 1 MHz. Both automatic and manual
scanning are permitted.

TABLE III. Susceptibility Scanning.

Analog Scans Stepped Scans

Frequency Range Maximum Scan Rate Maximum Step Size
30 Hz - 1 MHz 0.02 fo/sec 0.01 fo
1 MHz - 30 MHz 0.01 fo/sec 0.005 fo
30 MHz - 1 GHz 0.005 fo/sec 0.0025 fo
1 GHz - 8 GHz 0.002 fo/sec 0.001 fo
8 GHz - 40 GHz 0.001 fo/sec 0.0005 fo

The two primary areas of concern for frequency scanning for

susceptibility testing are response times for EUTs to react to
stimuli and how sharply the responses tune with frequency,
normally expressed as quality factor (Q). Both of these items
have been considered in the determination of the scan rates and
step sizes in Table III. The table entries are generally based
on the assumption of a maximum EUT response time of one second
and Q values of 50, 100, 200, 500, and 1000 (increasing values as
frequency increases in Table III). Since EUT responses are more
likely to occur in approximately the 1 to 200 MHz range due to
efficient cable coupling based on wavelength considerations, Q
values have been increased somewhat to slow the scan and allow
additional time for observation of EUT responses. More detailed
discussions on these items follow.

The assumption of a maximum response time of one second is

considered to be appropriate for a large percentage of possible
cases. There are several considerations. While the electronics

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APPENDIX

processing the interfering signal may respond quickly, the output

display may take some time to react. Outputs which require
mechanical motion such as meter movements or servo driven devices
will generally take longer to show degradation effects than
electronic displays such as video screens. Another concern is
that some EUTs will only be in particularly susceptible states
periodically. For example, sensors feeding information to a
microprocessor are typically sampled at specific time intervals.
It is important that the susceptibility stimuli be located at any
critical frequencies when the sensor is sampled. The time
intervals between steps and sweep rates in Table III may need to
be modified for EUTs with unusually long response times.

Some concern has been expressed on the susceptibility scan

rates and the impact that they would have on the length of time
required to conduct a susceptibility test. The criteria of Table
III allow the susceptibility scan rate to be adjusted continually
as the frequency is increased; however, as a practical matter,
the rate would most likely only be changed once every octave or
decade. As an example, Table A-I splits the frequency spectrum
up into ranges varying from octaves to decades and lists the
minimum time required to conduct a susceptibility test for an
analog scan. The scan rate for each range is calculated based on
the start frequency for the range. The total test time to run
RS103 from 1 MHz to 18 GHz is 76.3 minutes. A similar
calculation for a stepped scan results in a total test time which
is 2 times this value or 152.6 minutes. It must be emphasized
that the scan speeds should be slowed down if the EUT response
time or Q are more critical than those used to establish the
values in Table III.

Q is expressed as fo/BW where fo is the tuned frequency and

BW is the width in frequency of the response at the 3 dB down
points. For example, if a response occurred at 1 MHz at a
susceptibility level of 1 volt and the same response required
1.414 volts (3 dB higher in required drive) at 0.95 and 1.05 MHz,
the Q would be 1 MHz/(1.05 - 0.95 MHz) or 10. Q is primarily
influenced by resonances in filters, interconnecting cabling,
physical structure, and cavities. The assumed Q values are based
on observations from various types of testing. The step sizes in
Table III are one half of the 3 dB bandwidths of the assumed
value of Q ensuring that test frequencies will lie within the
resonant responses.

Below approximately 200 MHz, the predominant contributors

are cable and interface filter resonances. There is loading
associated with these resonances which dampens the responses and
limits most values of Q to less than 50. Above 200 MHz,
structural resonances of enclosures and housings start playing a
role and have higher values of Q due to less dampening. Above
approximately 1 GHz, aperture coupling with excitation of

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APPENDIX

cavities will be become dominant. Values of Q are dependent on

frequency and on the amount of material contained in the cavity.
Larger values of Q result when there is less material in the
volume. A densely packaged electronics enclosure will exhibit
significantly lower values of Q than an enclosure with a higher
percentage of empty volume. Q is proportional to Volume/(Surface
Area X Skin Depth). The value of Q also tends to increase with
frequency as the associated wavelength becomes smaller. EUT
designs with unusual configurations which result in high Q
characteristics may require that the scan rates and step sizes in
Table III be decreased for valid testing.

TABLE A-I. Susceptibility Testing Times

Frequency Range Maximum Actual

Scan Rate Scan Time
30 Hz - 100 Hz 0.6 Hz/sec 1.9 min
100 HZ - 1 kHz 2.0 Hz/sec 7.5 min
1 kHz - 10 kHz 20.0 Hz/sec 7.5 min
10 kHz - 100 kHz 200 Hz/sec 7.5 min
100 kHz - 1 MHz 2 kHz/sec 7.5 min
1 MHz - 5 MHz 10 kHz/sec 6.6 min
5 MHz - 30 MHz 50 kHz/sec 8.3 min
30 MHz - 100 MHz 150 kHz/sec 7.8 min
100 MHz - 200 MHz 500 kHz/sec 3.3 min
200 MHz - 400 MHz 1 MHz/sec 3.3 min
400 MHz - 1 GHz 2 MHz/sec 5.0 min
1 GHz - 2 GHz 2 MHz/sec 8.4 min
2 GHz - 4 GHz 4 MHz/sec 8.4 min
4 GHz - 8 GHz 8 MHz/sec 8.4 min
8 GHz - 12 GHz 8 MHz/sec 8.4 min
12 GHz - 18 GHz 12 MHz/sec 8.4 min
18 GHz - 30 GHz 18 MHz/sec 11.1 min
30 GHz - 40 GHz 30 MHz/sec 5.6 min

RF processing equipment presents a special case requiring

unique treatment. Intentionally tuned circuits for processing RF
can have very high values of Q. For example, a circuit operating

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APPENDIX

at 1 GHz with a bandwidth of 100 kHz has a Q of 1 GHz/100 kHz or

10,000.

Automatic leveling used to stabilize the amplitude of a test

signal for stepped scans may require longer dwell times than one
second at discrete frequencies. The signal will take time to
settle and any EUT responses during the leveling process should
be ignored.

40.10.4.2 (4.10.4.2.) Modulation of susceptibility signals.

Susceptibility test signals above 10 kHz shall be pulse modulated
at a 1 kHz rate with a 50% duty cycle unless otherwise specified
in an individual test method of this standard.

DISCUSSION: Modulation is usually the effect which degrades

EUT performance. The wavelengths of the RF signal cause
efficient coupling to electrical cables and through apertures (at
higher frequencies). Nonlinearities in the circuit elements
detect the modulation on the carrier. The circuits may then
respond to the modulation depending upon detected levels, circuit
bandpass characteristics, and processing features.

Pulse modulation at a 1 kHz rate, 50% duty cycle,

(alternately termed 1 kHz square wave modulation) is specified
for several reasons. One kHz is within the bandpass of most
analog circuits such as audio or video. The fast rise and fall
times of the pulse causes the signal to have significant harmonic
content high in frequency and can be detrimental to digital
circuits. Response of electronics has been associated with
energy present and a square wave results in high average power.
The modulation encompasses many signal modulations encountered in
actual use. The square wave is a severe form of amplitude
modulation used in communications and broadcasting. It also is a
high duty cycle form of pulse modulation representative of
radars.

Previous versions of MIL-STD-461 required that the worst

case modulation for the EUT be used. Worst case modulation
usually was not known or determined. Also, worst case modulation
may not be related to modulations seen in actual use or may be
very specialized. The most typical modulations used below
approximately 400 MHz have been amplitude modulation at either
400 or 1000 Hz (30 to 80%) or pulse modulation, 50% duty cycle,
at 400 or 1000 Hz. These same modulations have been used above
400 MHz together with pulse modulation at various pulse widths
and pulse repetition frequencies. Continuous wave (CW - no
modulation) has also occasionally been used. CW typically
produces a detected DC level in the circuitry and affects certain
types of circuits. In general, experience has shown that
modulation is more likely to cause degradation. CW should be
included as an additional requirement when assessing circuits

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APPENDIX

which respond only to heat such as electroexplosive devices. CW

should not normally be used as the only condition.

40.10.4.3 (4.10.4.3) Thresholds of susceptibility. When

susceptibility indications are noted in EUT operation, a
threshold level shall be determined where the susceptible
condition is no longer present. Thresholds of susceptibility
shall be determined as follows:

a. When a susceptibility condition exists, reduce the

interference signal until the EUT recovers.

b. Reduce the interference signal by an additional 6 dB.

c. Gradually increase the interference signal until the

susceptibility condition reoccurs. The resulting level
is the threshold of susceptibility.

d. Record this level, frequency range of occurrence,

frequency and test level of greatest susceptibility, and
other test parameters, as applicable.

DISCUSSION: It is usually necessary to test at levels above

MIL-STD-461 requirements to ensure that the test signal is at
least at the required level. Determination of a threshold of
susceptibility is necessary when degradation is present to assess
whether requirements are met. This information should be
included in the EMITR. Threshold levels below MIL-STD-461
requirements are unacceptable.

The specified steps to determine thresholds of

susceptibility standardize a particular technique. An
alternative method sometimes utilized in the past was to use the
value of the applied signal where the EUT recovers (step a above)
as the threshold. Hysteresis type effects are often present
where different values are obtained for the two methods.

40.11 (4.11) Calibration of measuring equipment and

antennas. Test equipment and accessories required for
measurement in accordance with this standard shall be calibrated
under an approved program in accordance with MIL-STD-45662. In
particular, measurement antennas, current probes, field sensors,
and other devices used in the measurement loop shall be
calibrated at least every 2 years unless otherwise specified by
the procuring activity, or when damage is apparent. Antenna
factors and current probe transfer impedances shall be determined
on an individual basis for each device.

DISCUSSION: Calibration is typically required for any

measurement device whose characteristics are not verified through

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use of another calibrated item during testing. For example, it

is not possible during testing to determine whether an antenna
used to measure radiated emissions is exhibiting correct gain
characteristics. Therefore, these antennas require periodic
calibration. Conversely, a power amplifier used during radiated
susceptibility testing often will not require calibration since
application of the proper signal level is verified through the
use of a separate calibrated field sensing device. Other
amplifier applications such as the use of a signal pre-amplifier
in front of a measurement receiver would require calibration of
the amplifier characteristics since the specific gain versus
frequency response is critical and is not separately verified.

40.11.1 (4.11.1) Measurement system test. At the start of

each emission test, the complete test system (including
measurement receivers, cables, attenuators, couplers, and so
forth) shall be verified by injecting a known signal, as stated
in the individual test method, while monitoring the system output
for the proper indication.

DISCUSSION: The end-to-end system check prior to emission

testing is valuable in demonstrating that the overall measurement
system is working properly. It evaluates many factors including
proper implementation of transducer factors and cable
attenuation, general condition and setting of the measurement
receiver, damaged RF cables or attenuators, and proper operation
of software. Details on implementation are included in the
individual test methods.

40.12 (4.12) Antenna factors. Factors for electric field

test antennas shall be determined in accordance with SAE ARP-958.

DISCUSSION: SAE ARP-958 provides a standard basis for

determining antenna factors for electric field emission testing.
A caution needs to be observed in trying to apply these factors
in applications other than EMI testing. The two antenna
technique for antennas such as the biconical and double ridge
horns is based on far field assumptions which are not met over
much of the frequency range. Although the factors produce
standardized results, the true value of the electric field is not
necessarily being provided through the use of the factor.
Different measuring sensors need to be used when the true
electric field must be known.

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50.0 MEASUREMENT PROCEDURES

TEST METHOD CE101:

This test method is used to measure emissions conducted from

the EUT on input power leads from 30 Hz to 10 kHz. It is not
applicable to power leads which supply power to other equipment.
Emission levels are determined by measuring the current present
on each power lead.

The LISNs will have little influence on the results of this

testing. The circuit characteristics of the LISN will help
stabilize measurements near 10 kHz; however, the LISN parameters
will not be significant over most of the frequency range of the
test.

Current is measured because of the low impedances present

over most of the frequency range of the test. Current levels
will be somewhat independent of power source impedance variations
as long as the impedance of the emission source is significant in
relation to the power source impedance. However, at frequencies
where the shielded room filters in the test facility resonate
(generally between 1 and 10 kHz), influences on measured currents
can be expected.

During the measurement system check, the signal generator

may need to be supplemented with a power amplifier to obtain the
necessary current 6 dB below the MIL-STD-461 limit.

A possible alternative measurement tool in this frequency

range is wave analyzer using a Fast Fourier Transform algorithm.
Use of this type of instrumentation requires specific approval by
the procuring activity.

TEST METHOD CE102:

This test method is used to measure emissions conducted from

the EUT on input power leads from 10 kHz to 10 MHz. It is not
applicable to power leads which supply power to other equipment.
Emission levels are determined by measuring the voltage present
at the output port on the LISN.

The power source impedance control provided by the LISN is a

critical element of this test. This control is imposed due to
wide variances in characteristics of shielded room filters and
power line impedances among various test agencies and to provide
repeatability through standardization. The LISN standardizes
this impedance. The impedance present at the EUT electrical
interface is influenced by the circuit characteristics of the

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APPENDIX

power lead wires to the LISNs. The predominant characteristic is

inductance. The impedance starts to deviate noticeably at
approximately 1 MHz where the lead inductance is about 13 ohms.

The upper measurement frequency is limited to 10 MHz because

of resonance conditions with respect to the length of the power
leads between the EUT and LISN. As noted in paragraph 4.8.5.2 of
the main body of the standard, these leads are between 2.0 and
2.5 meters long. Laboratory experimentation and theory show a
quarter-wave resonance close to 25 MHz for a 2.5 meter lead. In
the laboratory experiment, the impedance of the power lead starts
to rise significantly at 10 MHz and peaks at several thousand
ohms at approximately 25 MHz. Voltage measurements at the LISN
become largely irrelevant above 10 MHz.

The 0.25 microfarad coupling capacitor in the LISN allows

approximately 3.6 volts to be developed across the 50 ohm
termination on the signal port for 115 volt, 400 Hz, power
sources. The 20 dB attenuator is specified in the test method to
protect the measurement receiver and to prevent overload. 60 Hz
sources pose less of a concern.

dB
2

0
10 100 200
FREQUENCY (kHz)

FIGURE A-3. Correction factor for LISN capacitor.

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A correction factor must be included in the data reduction

to account for the 20 dB attenuator and for voltage drops across
the coupling capacitor. This capacitor is in series with a
parallel combination of the 50 ohm measurement receiver and the 1
kilohm LISN resistor. The two parallel resistances are
equivalent to 47.6 ohms. The correction factor equals
20 log10 ((1 + (7.48(10-5 )f)2)1/2/(7.48(10-5 )f)) where f is the
frequency of interest expressed in Hz. This equation is plotted
in Figure A-3. The correction factor is 4.46 dB at 10 kHz and
drops rapidly with frequency.

An area of concern for this test method is the potential to

overload the measurement receiver due to the current at the power
frequency. Overload precautions are discussed in paragraph 4.7.3
of this standard. When an overload condition is predicted or
encountered, a rejection filter can be used to attenuate the
power frequency. A correction factor must be then included in
the emission data to account for the filter loss with respect to
frequency.

TEST METHOD CE106:

This test method is used to measure spurious and harmonic

outputs appearing at the antenna port of transmitters. It is
also used to measure emissions at the antenna port of receivers,
amplifiers, and transmitters in the stand-by mode.

Since the test method measures emissions present on a

controlled impedance, shielded, transmission line, the
measurement results should be largely independent of the test
setup configuration. Therefore, it is not necessary to maintain
the basic test set described in the main body of this standard.

It is a direct coupled technique and does not consider the

effect that the antenna system characteristics will have on
actual radiated levels.

Figure CE106-1 is used for receivers, amplifiers, and

transmitters in the stand-by mode. The purpose of the attenuator
pad in Figure CE106-1 is to establish a low VSWR for more
accurate measurements. Its nominal value is 10 dB, but it can be
smaller, if necessary, to maintain measurement sensitivity.

The setup in Figure CE106-2 is used for low power

transmitters in which the highest intentionally generated
frequency does not exceed 26 GHz. The attenuator pad should be
approximately 20 dB or large enough to reduce the output level of
the transmitter sufficiently so that it does not damage or
overload the measurement receiver. The rejection network in the
figure is tuned to the fundamental frequency of the EUT and is
intended to reduce post-pad transmitter power to a level which

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APPENDIX

will not desensitize or induce spurious responses in the

measurement receiver. Both the rejection network and RF pad
losses must be adjusted to maintain adequate measurement system
sensitivity. The total power reaching the measurement receiver
input should not exceed the maximum allowable level specified by
the manufacturer. All rejection and filter networks must be
calibrated over the frequency range of measurement.

The setup of Figure CE106-3 is for transmitters with high

average power. For transmitters with an integral antenna, it is
usually necessary to measure the spurious emissions by the
radiated method RE103.

Some caution needs to be exercised in applying Table II of

the main body of this standard. For spurious and harmonic
emissions of equipment in the transmit mode, it is generally
desirable for the measurement receiver bandwidth to be
sufficiently large to include at least 90% of the power of the
signal present at a tuned frequency. This condition is required
if a comparison is being made to a power requirement in a
specification. Spurious and harmonic outputs generally have the
same modulation characteristics as the fundamental. Since this
method measures relative levels of spurious and harmonic signal
with respect to the fundamental, it is not necessary for the
measurement receiver to meet the above receiver bandwidth to
signal bandwidth criterion. However, if the measurement receiver
bandwidth does not meet the criterion and spurious and harmonic
outputs are located in frequency ranges where this standard
specifies a bandwidth different than that used for the
fundamental, the measurement receiver bandwidth should be changed
to that used at the fundamental to obtain a proper measurement.

For EUTs having waveguide transmission lines, the

measurement receiver needs to be coupled to the waveguide by a
waveguide to coaxial transition. Since the waveguide acts as a
high-pass filter, measurements are not necessary at frequencies
less than 0.8 fco, where fco is the waveguide cut-off frequency.

TEST METHOD CS101:

This test method is used to verify the ability of the EUT to

withstand ripple voltages present on power leads. Since the
applied voltage is coupled in series using a transformer,
Kirchoff’s voltage law requires that the voltage appearing across
the transformer output terminals must drop around the circuit
loop formed by the EUT input and the power source impedance. The
voltage specified by MIL-STD-461 is measured across the EUT input
because part of the transformer voltage can be expected to drop
across the source impedance.

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Earlier EMI standards introduced a circuit for a phase shift

network which was intended to cancel out AC power waveforms and
allow direct measurement of the ripple present across the EUT.
While these devices very effectively cancel the power waveform,
they return the incorrect value of the ripple and are not
acceptable for use. The networks use the principle of inverting
the phase of the input power waveform, adding it to the waveform
(input power plus ripple) across the EUT, and presumably
producing only the ripple as an output. For a clean power
waveform, the network would perform properly. However, the
portion of the ripple which drops across the power source
impedance contaminates the waveform and gets recombined with the
ripple across the EUT resulting in an incorrect value.

AC POWER
INPUTS ONLY

VOLTAGE
EUT
MONITOR

SIGNAL POWER
GENERATOR AMPLIFIER
DUMMY
LOAD
SAME
CURRENT
AS EUT

IDENTICAL
ISOLATION
TRANSFORMERS

FIGURE A-4. CS101 Power amplifier protection.

Voltages will appear across the primary side of the

injection transformer due to the EUT current load at the power
frequency. Larger current loads will result in larger voltages

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APPENDIX

and are the predominant concern. These voltages can cause

potential problems with the power amplifier. The circuit
arrangement in Figure A-4 will substantially reduce this voltage
and provide protection for the amplifier. This effect is
accomplished by using a dummy load equal to the EUT and wiring
the additional transformer so that its induced voltage is equal
to and 180 degrees out of phase with the induced voltage in the
injection transformer. If possible, the dummy load should have
the same power factor as the EUT.

The injected signal should be maintained as a sinusoid.

Saturation of the power amplifier or coupling transformer may
result in a distorted waveform.

TEST METHOD CS103:

This test method determines whether a receiver is free of

responses due to intermodulation products produced in the
receiver from two signals applied to the antenna port. No test
method is provided in the main body of this standard for this
requirement. Because of the large variety of receiver designs
being developed, the requirements for the specific operational
characteristics of a receiver must be established before
meaningful test procedures can be developed. Only general
testing techniques are discussed in this appendix.

Intermodulation testing can be applied to a variety of

receiving subsystems such as receivers, RF amplifiers,
transceivers and transponders.

Several receiver front-end characteristics must be known for

proper testing for intermodulation responses. These
characteristics generally should be determined by test. The
maximum signal input that the receiver can tolerate without
overload needs to be known to ensure that the test levels are
reasonable and that the test truly is evaluating intermodulation
effects. The bandpass characteristics of the receiver are
important for determining frequencies near the receiver
fundamental fo that will be excluded from test. Requirements for
this test are generally expressed in terms of a relative degree
of rejection by specifying the difference in level between
potentially interfering signals and the established sensitivity
of the receiver under test. Therefore, determination of the
sensitivity of the receiver is a key portion of the test.

The basic concept with this test is to combine two out-of-

band signals and apply them to the antenna port of the receiver
while monitoring the receiver for an undesired response. One of
the out-of-band signals is normally modulated with the modulation
expected by the receiver. The second signal is normally
continuous wave (CW). Figure A-5 shows a general setup for this

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APPENDIX

test. For applications where the receiver would not provide an

indication of interference without a receive signal being
present, a third signal can be used at the fundamental. This
arrangement may also be suitable for some receivers which process
a very specialized type of modulation which would never be
expected on an out-of-band signal. An option is for the two out-
of-band signals to be CW for this application.

SIGNAL
SOURCE NO. 1

FILTERS, MEASUREMENT
ATTENUATORS, RECEIVER
AS NEEDED

3 PORT 3 PORT
3 PORT EUT
NETWORK NETWORK,
NETWORK
IF NEEDED

FILTERS, FILTERS,
ATTENUATORS, OUTPUT
ATTENUATORS,
AS NEEDED MONITOR
AS NEEDED

SIGNAL SIGNAL
SOURCE NO. 2 SOURCE NO. 3,
IF NEEDED

FIGURE A-5. CS103 General test setup.

The frequency of the two out-of-band signals should be set

such that fo = 2f1 - f2 where fo is the tuned frequency of the
receiver and f1 and f2 are the frequencies of the signal sources.
This equation represents a third order intermodulation product,
which is the most common response observed in receivers. f1 and
f2 should be swept or stepped over the desired frequency range
while maintaining the relationship in the equation. It is
important to verify that any responses noted during this test are
due to intermodulation responses. Responses can result from
simply lack of rejection to one of the applied signals or from
harmonics of one of the signal sources. Turning off each signal

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APPENDIX

source in turn and noting whether the response remains can

demonstrate the source of the response.

For receivers with front-end mixing and filtering in an

antenna module, the test may need to be designed to be performed
on a radiated basis. All signals would need to be radiated and
assurances provided that any observed intermodulation products
are due to the receiver and not caused by items in the test area.
The EMITP would need to address antenna types, antenna locations,
antenna polarizations and field measurement techniques. This
test would probably need to be performed in an anechoic chamber.

For frequency hopping receivers, one possible approach is

choose an fo within the hop set and set up the signals sources as
described above. The performance of the receiver could then be
evaluated as the receiver hops. If the frequency hopping
receiver has a mode of operation using just one fixed frequency,
this mode should also be tested.

A common error made in performing this test method is

attributing failures to the EUT which are actually harmonics of
the signal source or intermodulation products generated in the
test setup. Therefore, it is important to verify that the
signals appearing at the EUT antenna port are only the intended
signals through the use of a measurement receiver as shown in
Figure A-5. Damaged, corroded, and faulty components can cause
signal distortion resulting in misleading results. Monitoring
will also identify path losses caused by filters, attenuators,
couplers, and cables.

Typical data for this test method for the EMITR are the
sensitivity of the receiver, the levels of the signal sources,
frequency ranges swept, operating frequencies of the receivers,
and frequencies and threshold levels associated with any
responses.

TEST METHOD CS104:

This test method determines whether a receiver is free of

responses from out-of-band signals applied to the antenna port.
No test method is provided in the main body of this standard for
this requirement. Because of the large variety of receiver
designs being developed, the requirements for the specific
operational characteristics of a receiver must be established
before meaningful test procedures can be developed. Only general
testing techniques are discussed in this appendix.

Front-end rejection testing can be applied to a variety of

receiving subsystems such as receivers, RF amplifiers,
transceivers and transponders.

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APPENDIX

Several receiver front-end characteristics must be known for

proper testing. These characteristics generally should be
determined by test. The maximum signal input that the receiver
can tolerate without overload needs to be known to ensure that
the test levels are reasonable. The bandpass characteristics of
the receiver are important for determining frequencies near the
receiver fundamental that will be excluded from testing.
Requirements for this test are often expressed in terms of a
relative degree of rejection by specifying the difference in
level between a potentially interfering signals and the
established sensitivity of the receiver under test. Therefore,
determination of the sensitivity of the receiver is a key portion
of the test.

The basic concept with this test method is to apply out-of-

band signals to the antenna port of the receiver while monitoring
the receiver for degradation. Figure A-6 shows a general test
setup for this test. There are two common techniques used for
performing this test using either one or two signal sources. For
the one signal source method, the signal source is modulated with
the modulation expected by the receiver. It is then swept over
the appropriate frequency ranges while the receiver is monitored
for unintended responses. With the two signal source method, a
signal appropriately modulated for the receiver is applied at the
tuned frequency of the receiver. The level of this signal is
normally specified to be close to the sensitivity of the
receiver. The second signal is unmodulated and is swept over the
appropriate frequency ranges while the receiver is monitored for
any change in its response to the intentional signal.

The two signal source method is more appropriate for most

receivers. The one signal source method may be more appropriate
for receivers which search for a signal to capture since they may
respond differently once a signal has been captured. Some
receivers may need to be evaluated using both methods to be
completely characterized.

For frequency hopping receivers, one possible approach is to

use a one signal method as if the EUT did not have a tuned
frequency (include frequency scanning across the hop set) to
evaluate the jamming/interference resistance of the receiver. If
a frequency hopping receiver has a mode of operation using just
one fixed frequency, this mode should also be tested.

For receivers with front-end mixing and filtering in an

antenna module, the test may need to be designed to be performed
on a radiated basis. All signals would need to be radiated and
assurances provided that any observed responses are due to the
receiver and not caused by items in the test area. The EMITP
would need to address antenna types, antenna locations, antenna

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APPENDIX

polarizations, and field measurement techniques. This test would

probably need to be performed in an anechoic chamber.

A common error made in performing this test method is

attributing failures to the EUT which are actually harmonics or
spurious outputs of the signal source. Therefore, it is
important to verify that the signals appearing at the EUT antenna
port are only the intended signals through the use of a
measurement receiver as shown in Figure A-6. Damaged, corroded,
and faulty components can cause signal distortion resulting in
misleading results. Monitoring will also identify path losses
caused by filters, attenuators, couplers, and cables.

FILTERS,
SIGNAL ATTENUATORS,
SOURCE NO. 1 AS NEEDED

MEASUREMENT
RECEIVER

3 PORT
NETWORK, 3 PORT
EUT
IF NEEDED NETWORK

OUTPUT
MONITOR
SIGNAL FILTERS,
SOURCE NO. 2, ATTENUATORS,
IF NEEDED AS NEEDED

FIGURE A-6. CS104 General test setup.

Typical data for this test method for the EMITR are the
sensitivity of the receiver, the levels of the signal sources,
frequency ranges swept, operating frequencies of the receivers,
degree of rejection (dB), and frequencies and threshold levels
associated with any responses.

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TEST METHOD CS105:

This test method determines whether a receiver is free of

responses due to modulation of an out-of-band signal being
transferred to an in-band signal at the antenna port. No test
method is provided in the main body of this standard for this
requirement. Because of the large variety of receiver designs
being developed, the requirements for the specific operational
characteristics of a receiver must be established before
meaningful test procedures can be developed. Only general
testing techniques are discussed in this appendix.

Cross modulation testing should be applied only to receiving

subsystems such as receivers, RF amplifiers, transceivers and
transponders which extract information from the amplitude
modulation of a carrier.

Several receiver front-end characteristics must be known for

proper testing for cross modulation responses. These
characteristics generally should be determined by test. The
maximum signal input that the receiver can tolerate without
overload needs to be known to ensure that the test levels are
reasonable. The bandpass characteristics of the receiver are
important for determining frequencies near the receiver
fundamental that will be excluded from test. Requirements for
this test are generally expressed in terms of a relative degree
of rejection by specifying the difference in level between
potentially interfering signals and the established sensitivity
of the receiver under test. Therefore, determination of the
sensitivity of the receiver is a key portion of the test.

The basic concept with this test is to apply a modulated

signal out-of-band to the receiver and to determine whether the
modulation is transferred to an unmodulated signal at the
receiver’s tuned frequency resulting in an undesired response.
There may be cases where the in-band signal needs to be modulated
if the receiver characteristics so dictate. The level of the in-
band signal is normally adjusted to be close to the receiver’s
sensitivity. The out-of-band signal is modulated with the
modulation expected by the receiver. It is then swept over the
appropriate frequency ranges while the receiver is monitored for
unintended responses. Testing has typically been performed over
a frequency range + the receiver intermediate frequency (IF)
centered on the receiver’s tuned frequency. Figure A-7 shows a
general setup for this test.

For receivers with front-end mixing and filtering in an

antenna module, the test may need to be designed to be performed
on a radiated basis. All signals would need to be radiated and
assurances provided that any responses are due to the receiver
and not caused by items in the test area. The EMITP would need

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APPENDIX

to address antenna types, antenna locations, antenna

polarizations and field measurement techniques. This test would
probably need to be performed in an anechoic chamber.

For frequency hopping receivers, one possible approach is

choose an fo within the hop set and set up the signals sources as
described above. The performance of the receiver could then be
evaluated as the receiver hops. If the frequency hopping
receiver has a mode of operation using just one fixed frequency,
this mode should also be tested.

FILTERS,
SIGNAL ATTENUATORS,
SOURCE NO. 1 AS NEEDED

MEASUREMENT
RECEIVER

3 PORT
NETWORK, 3 PORT
EUT
IF NEEDED NETWORK

OUTPUT
MONITOR
FILTERS,
SIGNAL ATTENUATORS,
SOURCE NO. 2 AS NEEDED

FIGURE A-7. CS105 General test setup.

It is important to verify that the signals appearing at the

EUT antenna port are only the intended signals through the use of
a measurement receiver as shown in Figure A-7. Damaged,
corroded, and faulty components can cause signal distortion
resulting in misleading results. Monitoring will also identify
path losses caused by filters, attenuators, couplers, and cables.

Typical data for this test method for the EMITR are the
sensitivity of the receiver, the levels of the signal sources,

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APPENDIX

frequency ranges swept, operating frequencies of the receivers,

and frequencies and threshold levels associated with any
responses.

TEST METHOD CS109:

This test method is used to verify the ability of the EUT to

withstand lower frequency currents flowing in its structure. It
is primarily intended to evaluate EUTs which include sensitive
low frequency receivers such as sonar.

Electrical connection needs to be made to the external

structure of the EUT and damage to the external finish should be
minimized. Screws or protuberances at ground potential near the
diagonal corners of the EUT should normally be used as test
points. Connections should be made with clip or clamp type
leads. If convenient test points are not available at the
diagonal corners, a sharply pointed test probe should be used to
penetrate the finish in place of the clip or clamp type lead.

TEST METHOD CS114:

This test method is used to verify the ability of the EUT to

withstand RF signals present on interconnecting cables. This
type of test is often considered as a bulk current test since
current is the parameter measured. However, it is important to
note that the test signal is inductively coupled and that
Faraday’s law predicts an induced voltage in a circuit loop with
the resultant current flow and voltage distribution dependent on
the various impedances present.

The loop circuit impedance measurement is strictly intended

to provide engineering information to assist in analysis of
results obtained for associated testing performed at the
platform-level. A common technique used to assess platform-level
performance is to illuminate the platform with low-level
electromagnetic fields while monitoring induced current levels on
cabling. The CS114 results can then be used to assess design
margins. However, differences in circuit impedances between the
laboratory and platform can cause perturbations between
laboratory and platform responses. The impedance information
from the CS114 test assists in assessing these differences.

Earlier versions of MIL-STD-462 included a test method CS02

which specified capacitive coupling of a voltage onto individual
power leads. As is the case for this test method, CS02 assessed
the effect of voltages induced from electromagnetic fields.
CS114 improves on CS02 by inducing levels on all wires at a
connector interface simultaneously (common mode) which better
simulates actual platform use. Also, a deficiency existed with

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APPENDIX

CS02 since the RF signals were induced only on power leads. This
test method is applicable to all EUT cabling.

An advantage of this type of conducted testing as compared

to radiated susceptibility testing is that voltage and current
levels can be more easily induced on the interfaces that are
comparable to those present in installations. The physical
dimensions of the EUT cabling in a test setup are often not large
enough compared to the installation for efficient coupling at
lower frequencies.

In the past, some platform-level problems on Navy aircraft

could not be duplicated in the laboratory using the standard test
methods in earlier versions of this standard. It was determined
that differences between the aircraft installation and laboratory
setups regarding the laboratory ground plane and avionics
(aircraft electronics) mounting and electrical bonding practices
were responsible. Most avionics are mounted in racks and on
mounting brackets. At RF, the impedances to general aircraft
structure for the various mounting schemes can be significantly
different than they are with the avionics mounted on a laboratory
ground plane. In the laboratory, it is not always possible to
produce a reasonable simulation of the installation. A ground
plane interference (GPI) test was developed to detect potential
failures due to the higher impedance. In the GPI test, each
enclosure of the EUT, in turn, is electrically isolated above the
ground plane and a voltage is applied between the enclosure and
the ground plane to simulate potential differences that may exist
in the installation. Since CS114 provides similar common mode
stresses at electrical interfaces as the GPI, the GPI is not
included in this standard. However, the Navy may prefer to
perform an additional susceptibility scan for aircraft
applications with an inductor placed between the EUT enclosure
and ground plane to more closely emulate the results of a GPI
setup. The primary side of a typical CS101 injection transformer
is considered to be an appropriate inductor.

CS114 has several advantages over the GPI as a general

evaluation method. The GPI often results in significant current
flow with little voltage developed at lower frequencies. CS114
is a controlled current test. A concern with the GPI test, which
is not associated with CS114, is that the performance of
interface filtering can be altered due to isolation of the
enclosure from the ground plane. The results of CS114 are more
useful since the controlled current can be compared with current
levels present in the actual installation induced from fields.
This technique has commonly been used in the past for
certification of aircraft as safe to fly.

Testing is required on both entire power cables and power

cables with the returns removed to evaluate common mode coupling

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 MIL-STD-462D
APPENDIX

to configurations which may be present in different

installations. In some installations, the power returns are
routed with the high side wiring. In other installations, power
returns are tied to system structure near the utilization
equipment with system structure being used as the power return
path.

A commonly used calibration fixture is shown in Figure A-8.

Other designs are available. The top is removable to permit the
lower frequency probes to physically fit. The calibration
fixture can be scaled to accommodate larger injection probes.

NOTE: VERTICAL CROSS-SECTION AT CENTER OF FIXTURE SHOWN

TOP SHALL BE REMOVEABLE

12.7 mm ALUMINUM,
120 mm WIDE

35 mm DIA TYPE N
CONNECTORS (2)
*
120 mm
12.7 mm ALUMINUM,
15 mm DIA 180 mm WIDE
BRASS
60 mm PLASTIC COATED
70 mm

230 mm

260 mm

* DIMENSIONS OF OPENING CRITICAL

FIGURE A-8. Typical CS114 calibration fixture.

Figure A-9 shows insertion loss characteristics for typical

injection probes. Insertion loss is the ratio of the power
applied to the probe when installed in the calibration fixture
and the power dissipated in one of the 50 ohm loads attached to
the fixture. Lower insertion loss indicates more efficient

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APPENDIX

coupling. Since power is equally divided between the two 50 ohm

loads, the lowest possible loss is 3 dB. Flat characteristics
with frequency are desirable to minimize the need for continuous
adjustment of signal sources.

Care needs to be taken in normalizing readings to the

amperes for one watt values specified in the test method since
there is a square relationship between current and power. For
example, if 0.001 watts of power results in 0.01 amperes of
current in the calibration fixture, the current for one watt is
equal to (1 watt/0.001 watts)1/2(0.01 amperes) = 0.32 amperes.

35

30

25
INSERTION LOSS (dB)

20

15

10

0
0.01 0.1 1 10 100 1000
FREQUENCY (MHz)

FIGURE A-9. Typical insertion loss of CS114 injection probes.

The loop circuit impedance evaluation for this test method

is the same as that used in CS116. This data should be used, if
available.

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APPENDIX

Techniques using network analyzers or spectrum analyzers

with tracking generators can simplify the measurements for both
paragraph 4.b calibration and paragraph 4.c EUT testing portions
of the method. For example, the output signal can first be set
to a predetermined value such as one milliwatt and the flatness
of the signal with frequency can be separately verified through a
direct connection to the receiver. With this same signal then
applied to the directional coupler, the induced level in the
calibration fixture can be directly plotted.

TEST METHOD CS115:

This test method is used to verify the ability of the EUT to

withstand transient waveforms excited by fast rise time pulses
coupled onto interconnecting cables. The excitation waveform
from the generator is a trapezoidal pulse. The actual waveform
on the interconnecting cable will be dependent on natural
resonance conditions associated with the cable and EUT interface
circuit parameters.

PULSE
RATE
CONTROL

VARIABLE
DC POWER
SUPPLY

HIGH VOLTAGE
COAXIAL RELAY

50 OHM COAXIAL
CHARGE LINE
50 OHM
COAXIAL
OUTPUT
CONNECTOR

50 OHM COAXIAL
OUTPUT LINE

FIGURE A-10. Circuit diagram of CS115 pulse generator.

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APPENDIX

A circuit diagram of the 50 ohm, charged line, pulse

generator required by CS115 is shown in Figure A-10. Its
operation is essentially the same as impulse generators used to
calibrate measurement receivers except that the pulse width is
much longer. A direct current power supply is used to charge the
capacitance of an open-circuited 50 ohm coaxial line. The high
voltage relay is then switched to the output coaxial line to
produce the pulse. The pulse width is dependent upon the length
of the charge line. The relay needs to have bounce-free contact
operation.

PULSE WIDTH MAINTAINED

AT > 30 NANOSECONDS

2
AMPERES

0
RISETIME AND FALLTIME
MAINTAINED AT < 2 NANOSECONDS
-2

-4

0 5 10 15 20 25 30 35 40
TIME (NANOSECONDS)

FIGURE A-11. Typical CS115 calibration fixture waveform.

Paragraph 4b(3) of CS115 requires verification that the rise

time, fall time, and pulse width portions of the applied waveform
are present in the observed waveform induced in the calibration
fixture. Figure A-11 shows a typical waveform that will be
present. Since the frequency response of injection probes falls
off at lower frequencies, the trapezoidal pulse supplied to the
probe sags in the middle portion of the pulse which is associated
with the lower frequency content of the applied signal. The
relevant parameters of the waveform are noted. It is critical

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APPENDIX

that an injection probe be used with adequate response at higher

frequencies to produce the required rise time and fall time
characteristics.

As also specified in CS114, testing is required on both

entire power cables and power cables with the returns removed to
evaluate common mode coupling to configurations which may be
present in different installations. In some installations, the
power returns are routed with the high side wiring. In other
installations, power returns are tied to system structure near
the utilization equipment with system structure being used as the
power return path.

Test method RS06 was previously included in MIL-STD-462.

RS06 was a formalization of the "chattering relay" test used
widely throughout the military aircraft industry. This method
improves on RS06. The chattering relay has been found to be
effective for determining upset conditions of equipment. The
basic concept was to electrically connect the relay coil in
series with a normally closed contact and allow the relay to
continuously interrupt itself. The wire between the coil and
contact was used to couple the transient onto EUT cables. The
greatest concern with the chattering relay is that it does not
produce a repeatable waveform since an arcing process is
involved. The particular relay being used and the condition of
its contact and coil mechanics play a large role. CS115 retains
the most important characteristic of the chattering relay which
is the fast rise time waveform and also has the important
advantage of a consistent excitation waveform.

The same calibration fixture used for CS114 can be used for
this test method. An available design is shown in Figure A-8.

TEST METHOD CS116:

This test method is used to verify the ability of the EUT to

withstand damped sine transients induced onto interconnecting
cables. In contrast to CS115 which excites natural resonances,
the intent of this test is to control the waveform as a damped
sine. Damped sine waveforms (sometimes complex combinations) are
a common occurrence on platforms from both external stimuli such
as lightning and electromagnetic pulse and from platform
electrical switching phenomena. Waveforms appearing on cables
can be due to the cable itself resonating or to voltage and
current drives resulting from other resonances on the platform.
Wide frequency coverage is included to account for a wide range
of conditions.

MIL-STD-462 previously included test methods CS10, CS11,

CS12, and CS13 which addressed various types of damped sine
testing on both cables and individual circuits or connector pins.

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APPENDIX

This test method is a single replacement for all those methods.

CS116 addresses testing of cables (interconnecting including
power) and individual power leads. The common mode cable portion
of the test is the best simulation of the type of condition
present on platforms from electromagnetic field excitation.
The individual power lead test addresses differential type
signals present on platforms from switching functions occurring
in the power system.

As necessary, the test can be applied in a straightforward

manner to wires on individual pins on an EUT connector or to
individual circuits (twisted pairs, coaxial cables, and so
forth).

Since the quality factor (Q) of the damped sine signal

results in both positive and negative peaks of significant value
regardless of the polarity of the first peak, there is no
requirement to switch the polarity of the injected signal.

The common mode injection technique used in this method and

other methods such as CS114 is a partial simulation of the actual
coupling mechanism on platforms. The magnetic field in the
injection device is present at the physical location of the core
of the injection device. In the platform, the electromagnetic
field will be distributed in space. The injection probe induces
a voltage in the circuit loops present with the voltage dropping
and current flowing based on impedances present in the loop.
There is a complex coupling relationship among the various
individual circuits within the cable bundle. The injection probe
is required to be close to the EUT connector for standardization
reasons to minimize variations particularly for higher
frequencies where the shorter wavelengths could affect current
distribution.

A loop circuit impedance evaluation is required to identify

impedance maximum and minimum. Voltage and current,
respectively, will be maximized during testing at the associated
frequencies, thus providing maximum stress on the EUT. This
procedure is done to ensure performance of the EUT in the
installation when worst-case coupling occurs. The loop circuit
impedance evaluation is also required by CS114 and that data
should be used when available.

TEST METHOD RE101:

This test method is used to measure magnetic field emissions

radiated from the EUT and associated cabling. A 13.3 cm loop is
specified for the test.

Two measurement distances of 7 and 50 centimeters are

specified to allow for evaluation of potential impacts in the

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APPENDIX

actual installation. There may be instances where potentially

sensitive equipment is a sufficient distance from the point of
emissions that a 50 centimeter control distance is adequate.

If the maximum level is always observed on one face or on

one cable at all frequencies, then data only needs to be recorded
for that face or cable.

Typical points of magnetic field emissions leakage from EUT

enclosures and cables are cable shield terminations, CRT yokes,
transformers and switching power supplies.

A possible alternative measurement tool in this frequency

range is wave analyzer using a Fast Fourier Transform algorithm.
Use of this type of instrumentation requires specific approval by
the procuring activity.

TEST METHOD RE102:

This test method is used to measure electric field emissions

radiating from the EUT and associated cabling.

Specific antennas are required by this method for

standardization reasons. The intent is to obtain consistent
results between different test facilities.

In order for adequate signal levels to be available to drive

the measurement receivers, physically large antennas are
necessary. Due to shielded room measurements, the antennas are
required to be relatively close to the EUT, and the radiated
field is not uniform across the antenna aperture. For electric
field measurements below several hundred megahertz, the antennas
do not measure the true electric field.

The 104 centimeter rod antenna has a theoretical electrical

length of 0.5 meters and is considered to be a short monopole
with an infinite ground plane. It would produce the true
electric field if a sufficiently large counterpoise were used to
form an image of the rod in the ground plane. However, there is
not adequate room. The requirement to bond the counterpoise to
the shielded room or earth ground, as applicable, is intended to
improve its performance as a ground plane. The biconical and
double ridged horn antennas are calibrated using far-field
assumptions at a 1 meter distance. This technique produces
standardized readings. However, the true electric field is
obtained only above approximately 1 GHz where a far field
condition exists for practical purposes.

Antenna factors are determined using the procedures of SAE

ARP-958. They are used to convert the voltage at the measurement
receiver to the field strength at the antenna. Any RF cable loss

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 MIL-STD-462D
APPENDIX

and attenuator values must be added to determine the total

correction to be applied.

Previous versions of this standard specified conical log

spiral antennas. These antennas were convenient since they did
not need to be rotated to measure both polarizations of the
radiated field. The double ridged horn is considered to be
better for standardization for several reasons. At some
frequencies, the antenna pattern of the conical log spiral is not
centered on the antenna axis. The double ridged horn does not
have this problem. The circular polarization of the conical log
spiral creates confusion in its proper application. Electric
fields from EUTs would rarely be circularly polarized.
Therefore, questions are raised concerning the need for 3 dB
correction factors to account for linearly polarized signals.
The same issue is present when spiral conical antennas are used
for radiated susceptibility testing. If a second spiral conical
is used to calibrate the field correctly for a circularly
polarized wave, the question arises whether a 3 dB higher field
should be used since the EUT will respond more readily to
linearly polarized fields of the same magnitude.

Other linearly polarized antennas such as log periodic

antennas are not to be used. It is recognized that these types
of antennas have sometimes been used in the past; however, they
will not necessarily produce the same results as the double
ridged horn because of field variations across the antenna
apertures and far field/near field issues. Uniform use of the
double ridge horn is required for standardization purposes to
obtain consistent results among different test facilities.

Normally, a horn antenna is used above 10 GHz. Caution

should be exercised to select antennas which have patterns with
broad beamwidths.

The stub radiator required by the method is simply a short

wire (approximately 10 centimeters) connected to the center
conductor of a coaxial cable which protrudes from the end of the
cable.

There are two different mounting schemes for baluns of

available 104 centimeter rod antennas with respect to the
counterpoise. Some are designed to be mounted underneath the
counterpoise while others are designed for top mounting. Either
technique is acceptable provided the desired 0.5 meter electrical
length is achieved with the mounting scheme.

The antenna positioning requirements in this method are

based on likely points of radiation and antenna patterns. At
frequencies below several hundred MHz, radiation is most likely
to originate from EUT cabling. The 104 centimeter rod and

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APPENDIX

biconical antennas have wide pattern coverage. The equation in

Figure RE102-3 is based on the rod and biconical being placed at
least every 3 meters along the test setup boundary. The double
ridge horns have narrower beamwidths. However, the shorter
wavelengths above 200 MHz will result in radiation from EUT
apertures and portions of cabling close to EUT interfaces. The
requirements for antenna positioning above 200 MHz are based on
including EUT apertures and lengths of cabling at least one
quarter wavelength.

All the specified antennas are linearly polarized. Above 30

MHz, measurements must be performed to measure both horizontal
and vertical components of the radiated field. Measurements with
the 104 centimeter rod are performed only for vertical
polarization. This antenna configuration is not readily adapted
for horizontal measurements.

For equipment or subsystems which have enclosures or cabling

in various parts of a platform, data may need to be taken for
more than one configuration. For example, in an aircraft
installation where a pod is located outside of aircraft structure
and its associated cabling is internal to structure, two
different MIL-STD-461 limits may be applicable. Different sets
of data may need to be generated to isolate different emissions
from the pod housing and from cabling. The non-relevant portion
of the equipment would need to be protected with appropriate
shielding during each evaluation.

TEST METHOD RE103:

This test method is used to measure spurious and harmonic

outputs of transmitters in the far field. It is a radiated
technique and therefore includes the antenna system
characteristics.

Since the test method measures emissions radiating from an

antenna connected to a controlled impedance, shielded,
transmission line, the measurement results should be largely
independent of the test setup configuration. Therefore, it is
not necessary to maintain the basic test set described in the
main body of this standard.

The test methodology is laborious and will require a large

open area to meet antenna separation distances. Equations in the
test method specify minimum acceptable antenna separations based
on antenna size and operating frequency of the EUT. Antenna
pattern searches in both azimuth and elevation are required at
the spurious and harmonic emissions to maximize the level of the
detected signal and account for antenna characteristics.

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 MIL-STD-462D
APPENDIX

Sensitivity of the measurement system may need enhancement

by use of preamplifiers and the entire test needs to be
coordinated with local frequency allocation authorities. All
recorded data has to be corrected for space loss and antenna gain
before comparisons to the limit.

As shown in Figures RE103-1 and RE103-2, shielding might be

necessary around the measurement system and associated RF
components to prevent the generation of spurious responses in the
measurement receiver. The need for such shielding can be
verified by comparing measurement runs with the input connector
of the measurement receiver terminated in its characteristic
impedance and with the EUT in both transmitting and stand-by
modes or with the EUT turned off. Also, the receiving or
transmit antenna may be replaced with a dummy load to determine
if any significant effects are occurring through cable coupling.

The RF cable from the receive antenna to the measurement

receiver should be kept as short as possible to minimize signal
loss and signal pick-up.

The band-rejection filters and networks shown in Figures

RE103-1 and RE103-2 are needed to block the transmitter
fundamental and thus reduce the tendency of the measurement
receiver to generate spurious responses or exhibit suppression
effects because of the presence of strong out-of-band signals.
These rejection networks and filters require calibration over the
frequency range of test.

Some caution needs to be exercised in applying Table II of

the main body of this standard. In paragraph 4d(4) of the test
method, a power monitor is used to measure the output power of
the EUT. In conjunction with the antenna gain, this value is
used to calculate the effective radiated power (ERP) of the
equipment. In paragraph 4d(5) of the test method, the
measurement receiver is used to measure the power from a
receiving antenna. This result is also used to calculate an
ERP. For the 2 measurements to be comparable, the measurement
receiver bandwidth needs to be sufficiently large to include at
least 90% of the power of the signal present at the tuned
frequency. If the bandwidth in Table II of the main body of the
standard is not appropriate, a suitable measurement receiver
bandwidth should be proposed in the EMITP.

TEST METHOD RS101:

This test method is used to verify the ability of the EUT to

withstand lower frequency magnetic fields. This test is
primarily intended to evaluate low frequency receivers which
operate within the frequency range of the test.

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 MIL-STD-462D
APPENDIX

Laboratory tests have been performed to assess the

possibility of using the 13.3 centimeter loop sensor specified in
Test Method RE101 instead of the 4 centimeter loop sensor in this
test method to verify the radiated field. The testing revealed
that the 13.3 centimeter loop sensor did not provide the desired
result due to variation of the radiated field over the area of
the loop sensor. Due to its smaller size, the 4 centimeter loop
sensor provides an accurate measure of the field near the axis of
the radiating loop.

TEST METHOD RS103:

This test method is used to verify that the EUT does not
respond to radiated electric fields.

Test facilities are permitted to select appropriate electric

field generating apparatus. Any electric field generating device
such as antenna, long wire, TEM cell, reverberating chamber (when
approved by the procuring activity) or parallel strip line
capable of generating the required electric field may be used.
Fields should be maintained as uniform as possible over the test
setup boundary. Above 30 MHz, both horizontally and vertically
polarized fields must be generated. This requirement may limit
the use of certain types of apparatus. Only vertically polarized
measurements are required below 30 MHz due to the difficulty of
orienting available test equipment for horizontal measurements.

TEM cells, reverberating chambers or other unconventional

techniques require approval since they may be unsuitable for
certain applications. Procuring agencies must consider a number
of issues in deciding whether to allow the use of these
alternative techniques for a particular procurement. Issues
relating to TEM cells and reverberation chambers are discussed
below.

TEM cells produce relatively uniform fields at modest power

input levels. TEM cells are shielded volumes with a center plate
which is driven by a signal source. A plane wave is propagated
between the center plate and the upper and lower surfaces.
There are several concerns with TEM cells. Only vertically
polarized electric fields are produced. While some EUT
enclosures can be placed in several orientations for assessment,
proper evaluation of coupling to any electrical interface cabling
is difficult. There is usually no convenient method to expose
the cabling to electric fields aligned with the cabling. Since
the EUT is usually placed on the center plate (which is the
driven element), the requirements in the general portion of this
standard for use of ground planes cannot be implemented. Space
limitations are a potential problem because of the 2 meter
required lengths of cabling. Multiple EUT enclosures can
exacerbate this situation.

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 MIL-STD-462D
APPENDIX

Reverberating chambers, using mode stirred techniques, have

been popular for performing shielded effectiveness evaluations
and, in some cases, have been used for radiated susceptibility
testing of equipment and subsystems. The concept used in
reverberating chambers is to excite available electromagnetic
wave propagation modes to set up variable standing wave patterns
in the chamber. A transmit antenna is used to launch a
electromagnetic wave. An irregular shaped paddle wheel (mode
stirrer) is rotated to excite the different modes and modify the
standing wave pattern in the chamber. Any physical location in
the chamber will achieve same peak field strength at some
position of the paddle wheel.

Reverberation chambers have the advantage of producing

relatively higher fields than other techniques for a particular
power input. Also, the orientation of EUT enclosures is less
critical since the all portions of the EUT will be exposed to the
same peak field at some paddle wheel position. The performance
of a particular reverberation chamber is dependent upon a number
of factors including dimensions, Q of the chamber, number of
available propagation modes, and frequency range of use.

However, there are some concerns. The field polarization

and distribution with respect to the EUT layout are generally
unknown at a point in time. If a problem is noted, the point of
entry into the EUT may not be apparent. Since paragraph 4.10.4.2
of the main body of the standard requires a one second dwell time
to allow the EUT to respond to the susceptibility signal, the
paddle wheel must be maintained at each position for one second.
If the paddle wheel has 100 positions, 100 seconds is required
for a particular tuned frequency. The maximum step sizes listed
in Table III of the main body are based on assumed Q values that
could be present in the EUT and associated cabling. If the
signal source is stepped in increments of the indicated sizes,
test times could become excessively long. For this example, test
time would be approximately 100 times greater than using a
conventional radiating antenna technique. The procuring activity
could approve a change to the step size or dwell time
requirements taking on some risk that an EUT response would be
missed at some frequencies. The performance of a particular
chamber must be reviewed to determine the criticality of these
concerns.

Reverberation chambers are sometimes treated as a good tool

to determine potential problem frequencies with conventional
antenna methods being used to evaluate areas of concern.

Monitoring requirements emphasize measuring true electric

field. While emission testing for radiated electric fields does
not always measure true electric field, sensors with adequate
sensitivity are available for field levels generated for

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 MIL-STD-462D
APPENDIX

susceptibility testing. Physically small and electrically short

sensors are required so that the electric field does not vary
substantially over the pickup element resulting in the
measurement of a localized field. Broadband sensors not
requiring tuning are available.

The use of more than one sensor is acceptable provided all

sensors are within the beamwidth of the transmit antenna. The
effective field is determined by taking the average of the
readings. For example, if the readings of three sensors are 30,
22, and 35 volts/meter, the effective electric field level is
(30 + 22 + 35)/3 = 29 volts/meter.

Different sensors may use various techniques to measure the

field. At frequencies where far-field conditions do not exist,
sensors must be selected which have electric field sensing
elements. Sensors which detect magnetic field or power density
and convert to electric field are not acceptable. Under far-
field conditions, all sensors will produce the same result.
Correction factors must be applied for modulated test signals for
equivalent peak detection as discussed under paragraph 4.9.1. A
typical method for determining the correction factor for these
sensors is as follows:

1. Generate a field at a selected frequency using an

unmodulated source.

2. Adjust the field to obtain a reading on the sensor

display near full scale and note the value.

3. Modulate the field as required (normally 1 kHz pulse,

50% duty cycle) and ensure the field has the same peak value. A
measurement receiver with the peak detector selected and
receiving antenna can be used to make this determination.

4. Note the reading on the sensor display.

5. Divide the first reading by the second reading to

determine the correction factor (Subtract the two readings if the
field is displayed in terms of dB).

6. Repeat the procedure at several frequencies to verify

the consistency of the technique.

Above 1 GHz, radiated fields usually exhibit far-field

characteristics for test purposes due to the size of typical
transmit antennas, antenna patterns, and distances to the EUT.
Therefore, a double ridged horn together with a measurement
receiver will provide true electric field. Similarly, the
particular sensing element in an isotropic sensor is not

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 MIL-STD-462D
APPENDIX

critical, and acceptable conversions to electric field can be

made.

For equipment or subsystems which have enclosures or cabling

in various parts of a platform, data may need to be taken for
more than one configuration. For example, in an aircraft
installation where a pod is located outside of aircraft structure
and its associated cabling is internal to structure, two
different MIL-STD-461 limits may be applicable. Different sets
of data may need to be generated to evaluate potential pod
susceptibility due to coupling through the housing versus
coupling from cabling. The non-relevant portion of the equipment
would need to be protected with appropriate shielding.

TEST METHOD RS105:

This test method is used to verify the ability of EUT to

withstand the fast rise time, free-field, transient conditions of
electromagnetic pulse (EMP). It is intended to be used for
equipment enclosures which are directly exposed to the incident
field outside of platform structure. EUT cabling is not
evaluated as part of this test. Effects due to cable coupling
are tested under CS116. To protect the EUT and monitoring and
simulation equipment, all cabling should be treated with overall
shielding.

The EMP field is simulated in the laboratory using bounded

wave TEM radiators such as TEM cells and parallel plate
transmission lines. To ensure that the EUT does not
significantly distort the field in the test volume, the EUT
dimensions should be no more than a third of the dimension
between the sides of the simulator. In these simulators the
electric field is perpendicular to the surfaces of the radiator.
Since the polarization of the incident EMP field in the
installation is not known, the EUT must be tested in all
orthogonal axes.

Since this test may cause damage to the EUT, it is advisable

to first test at 50% of the specified limit, with two pulses, and
then increase the amplitude slowly until the specified limit is
reached.

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