Operation Manual

Bently Nevada™ Asset Condition Monitoring

Differential Expansion Transducer

System

Part Number 105826-01

Rev. F (09/07)
Differential Expansion Transducer System Operation Manual

Copyright 1993. Bently Nevada LLC.

All rights reserved.

The information contained in this document is subject to change without notice.

The following are trademarks of General Electric Company in the United States and other
countries:

CableLoc, Keyphasor and Proximitor

The following are trademarks of the legal entities cited:

Teflon® and Viton® are registered trademarks of Dupont.

Sealtite® is a registered trademark of Anaconda Wire and Cable Company.
Loctite® is a registered trademark of Anaconda Wire and Cable Company.

Contact Information

The following ways of contacting Bently Nevada are provided for those times when you
cannot contact your local representative:

Mailing Address 1631 Bently Parkway South

Minden, Nevada USA 89423
USA
Telephone 1.775.782.3611
1.800.227.5514
Fax 1.775.215.2873
Internet www.ge-energy.com/bently

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 Additional Information
Product Disposal Statement
Customers and third parties, who are not member states of the European Union, who are
in control of the product at the end of its life or at the end of its use, are solely
responsible for the proper disposal of the product. No person, firm, corporation,
association or agency that is in control of product shall dispose of it in a manner that is
in violation of any applicable federal, state, local or international law. Bently Nevada LLC
is not responsible for the disposal of the product at the end of its life or at the end of its
use.

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Differential Expansion Transducer System Operation Manual

Contents
1. System Description ........................................................................................2
1.1 The Transducer System.................................................................................................................. 2
1.2 Unique Features of the Transducer ......................................................................................... 2
1.3 Theory of Operation ......................................................................................................................... 3
2. Installation.......................................................................................................5
2.1 Planning the Installation ................................................................................................................ 5
2.1.1 Picking the Mounting Location............................................................................................... 5
2.1.2 Checking the Environmental Conditions............................................................................ 8
2.1.3 Evaluating the Observed Surface ......................................................................................... 9
2.1.4 Verifying the Mounting Location .........................................................................................11
2.1.5 Transducer Separation ............................................................................................................12
2.2 Mounting the Transducer ............................................................................................................12
2.2.1 Installing the Mounting Bracket...........................................................................................13
2.2.2 Checking the Mounting Holes...............................................................................................13
2.2.3 Installing the Transducer in the Mounting Bracket.....................................................13
2.3 Checking the Transducer Installation ....................................................................................14
2.3.1 Gapping the Transducer .........................................................................................................16
2.4 Common Transducer Installation Errors...............................................................................19
3. Maintenance
................................................................................................20
3.1 Recommended Maintenance Equipment ............................................................................20
3.2 Storing the System..........................................................................................................................20
3.3 Verification Test ...............................................................................................................................21
3.4 Troubleshooting ...............................................................................................................................23

4. Glossary........................................................................................................28
5. Appendix A Ordering Information .............................................................31
5.1 Receiving and Inspecting Your Order.....................................................................................31
5.2 Ordering Information.....................................................................................................................32
6. Appendix B Optional Accessories ..............................................................36
6.1 Housings..............................................................................................................................................36
6.2 Transducer Accessories ...............................................................................................................37
7. Appendix C Mechanical Drawings
.............................................................40

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8. Appendix D Specifications
.......................................................................... 45
9. Appendix E Sensitivity Curves ................................................................... 49
10. Index ........................................................................................................... 55

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Differential Expansion Transducer System Operation Manual

1. System Description
This section describes the 25mm Differential Expansion Transducer System and
explains the theory of operation of the transducer.

1.1 The Transducer System

The 25mm Differential Expansion Transducer shown in Figure 1-1 measures the
differential expansion between the rotor and the stationary parts of a steam turbine. The
transducer is environmentally rugged and designed to withstand the harsh conditions
commonly found inside steam turbines.

1.2 Unique Features of the Transducer

The 25mm Differential Expansion Transducer has many unique features:
• Integral electronics eliminate the need for an external Proximitor® sensor
or special extension cables. This design lets you trim or splice the
transducer cable to the desired length in the field without affecting the
transducer scale factor.
• The transducer cable is a 3 conductor twisted cable allowing ring-lug
termination. The cable has a braided shield with an integral drain wire for
easy termination.

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 Section 1 - System Description

• Each transducer is adjusted for linearity and temperature stability using

digital techniques. This adjustment provides high accuracy and stability.
• Rugged construction using polyphenylene sulfide (PPS) thermoplastic and
Viton o-rings protects the transducer from the harsh environments
commonly found in steam turbines.
• The transducer is water resistant and is rated for 100% relative humidity
condensing atmosphere conditions.

1.3 Theory of Operation

The 25mm Differential Expansion Transducer uses the eddy current principle to
measure the distance between the transducer tip and a conductive surface.
Figure 3-1 illustrates how this principle works.

The inductance in the transducer coil and the capacitance in the transducer
circuitry form an LC circuit which oscillates when energized. This oscillation sends
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Differential Expansion Transducer System Operation Manual
an alternating current through the coil in the tip of the transducer. This current
generates an alternating magnetic field around the transducer tip as shown in
Figure 1-3.
As a conductive surface approaches the transducer tip, the magnetic field
induces small eddy currents in the conductive material that remove energy from
the magnetic field. As the conductive material gets closer to the transducer tip,
more eddy currents are generated causing more energy loss from the magnetic
field. The transducer circuitry senses the energy loss and generates an output
voltage which is proportional to the distance between the transducer tip and the
conductive surface.

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 Section 2 - Installation

2. Installation

This section shows how to install the 25mm transducer to measure differential
expansion. Use this approach to install the transducer.
• Plan the Installation
• Mount the Transducer
• Check the Installation
• Gap the Transducer
• Connect the Transducer Wiring
For information about applications other than differential expansion, contact your
local Bently Nevada Corporation office.

2.1 Planning the Installation

To ensure that the installed system will work properly, we recommend that you
consider the following items before you install the system.
• Pick an appropriate mounting location for the transducer.
• Check that the environmental conditions at the transducer mounting site
are within the specifications of the system.
• Verify that the observed surface is a suitable target for the transducer.

• Verify that the mounting location gives adequate side clearance and
transducer separation.

2.1.1 Picking the Mounting Location

CAUTION

Measurement errors may occur if the 25mm

Differential Expansion Transducer is used for
vibration or Keyphasor measurements. The
frequency response of the transducer is much
lower than that of most transducers used for those
measurements. Refer to Appendix D for detailed
specifications.
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Differential Expansion Transducer System Operation Manual
Differential expansion is the measurement of the axial position of the rotor with
respect to the machine casing. Changes in axial rotor position relative to the
casing affect axial clearances and are usually caused by thermal expansion or
contraction during startup, normal operation, and shutdown. Although this
parameter is usually measured at the opposite end of the machine from the
thrust bearing, it can be measured at any location that provides a good reference
of the relative axial position between the rotating and stationary elements of the
machine. This relative axial position is usually measured with an eddy-current
transducer mounted to a non-rotating element such as the case, nozzle blocks, or
guide vanes. The transducer is positioned to directly observe a surface that is
connected to the rotating element like the rotor collar or ramp surface. Figure
2-1 through Figure 2-3 show typical transducer installations.

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Section 2 - Installation

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Differential Expansion Transducer System Operation Manual

2.1.2 Checking the Environmental Conditions

Although the transducer is designed to withstand the harsh environment for most
differential expansion applications, check that the temperature, pressure, and
exposure to chemicals and moisture are within the specifications of the system.

2.1.2.1 Operating Temperature

CAUTION
Exposing the 25mm Differential Expansion
Transducer to temperatures above its maximum
rating may result in reduced accuracy and
eventually cause permanent damage to the
transducer. Do not expose the transducer to
temperatures above 125°C (257°F).
The 25mm Differential Expansion Transducer is usually located in an oil
environment which rarely exceeds the maximum rated temperature of the
transducer. However, if the transducer is located in the condenser of a steam
turbine and the vacuum in the condenser is lost during a machine coast down,
the transducer may be exposed to wet steam under pressure. This steam can
increase the internal temperature of the turbine above 125°C (257°F) and
damage the transducer. This situation can be avoided by maintaining a vacuum
in the turbine section where the transducer is located while the machine is
operating. The vacuum will usually keep temperatures low enough to avoid
damage to the transducer.

2.1.2.2 Pressure Sealing

25 mm DE Transducers are designed to seal differential pressure between the

probe tip and case. The probe sealing material consists of a Viton® O-ring.
Probes are not pressure tested prior to shipment. Contact our custom design
department if you require a test of the pressure seal for your application.
It is the responsibility of the customer or user to ensure that all liquids and gases
are contained and safely controlled should leakage occur from a proximity
transducer. In addition, solutions with high or low pH values may erode the tip
assembly of the probe causing media leakage into surrounding areas. Bently
Nevada Corporation will not be held responsible for any damages resulting from
leaking 25 mm DE transducers. In addition, 25 mm DE transducers will not be
replaced under the service plan due to probe leakage.

2.1.2.3 Chemical Compatibility

Although the 25mm Differential Expansion Transducers are compatible with

many types of harsh chemical environments, certain chemicals can damage the
transducer. Potentially damaging chemicals include strong acids (pH < 4), strong
bases (pH > 10), and some organic solvents (like dimethyl formamide). See
8
 Section 2 - Installation
Appendix D for more information on chemical compatibility. Contact the nearest
Bently Nevada Corporation office if you need assistance in determining chemical
compatibility.

2.1.2.4 Moisture Sealing

Protect splices and connections in the cable by using terminal blocks in the
appropriate housing. Appendix B shows these blocks and housings.

CAUTION

Oil mist will dissolve the adhesive on electrical tape

causing the connections to become contaminated. Do
not use adhesive electrical tape to protect splices or
connections.

It may be necessary to seal around the transducer cable where it leaves the
machine casing. Sealing creates a special problem because the cable's Teflon
insulation will cold flow if it is subjected to the high pressure exerted by most
sealing arrangements. If the pressure differential across the seal area is 1.75
atmospheres or less, use a low pressure cable seal such as Bently Nevada part
number 43501. Even with the low pressure seal, liquid can wick between the
cable outer jacket and the inner conductors. If the differential pressure is greater
than 1.75 atmospheres, you must use a high pressure feedthrough. Contact your
nearest Bently Nevada office for more information.

2.1.3 Evaluating the Observed Surface

Proper operation of the transducer requires that the observed surface meet
critical specifications for size, material, and surface quality.

2.1.3.1 Target Size

To obtain the full range and sensitivity of the transducer system, the minimum
collar dimensions should meet those specified in Figure 2-4.
Some installations have insufficient collar height to meet the transducer
requirements. Appendix E shows the 25mm Differential Expansion Transducer
response for targets that do not meet the minimum specified.

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Differential Expansion Transducer System Operation Manual

B = 38 mm (1.50 in)
D = 67 mm (2.63 in)

2.1.3.2 Observed Surface Considerations

The transducer accuracy depends on certain characteristics of the observed

shaft:
• Observed surface material
• Plated surface problems
• Mechanical and electrical Runout
These factors are important in obtaining accurate response and reliable
measurements with the 25mm Differential Expansion Transducer.

Observed Shaft Material

Bently Nevada transducers are factory adjusted to AISI 4140 alloy steel. Most AISI
1000 and AISI 4000 Series steels will result in a response curve similar to the AISI
4140 Series steel. However, other types of metal such as copper, aluminum,
brass, tungsten carbide, stainless steel, and chrome plating will result in a
different transducer response curve. The 25mm Differential Expansion
Transducer can be factory adjusted to other materials by Bently Nevada
Corporation. If the shaft material has significantly different magnetic and
electrical properties than AISI 4140 steel, contact a Bently Nevada Corporation
office for assistance.

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 Section 2 - Installation
Plated Surfaces
If the shaft target area is plated, either remove the plating material, or contact the
nearest Bently Nevada Corporation office for assistance. When plating is applied
to the observed surface of a shaft, the sensitivity of the transducer will change.
Since the transducer senses below the surface of the shaft material, its sensitivity
can be affected by the type and thickness of the plating. For example, if the
target material is chrome plated, the plating must be uniform and at least 0.76
mm (20 mils) deep.

Mechanical and Electrical Runout

Proper transducer installation requires that the shaft target area be free of
surface irregularities and residual magnetism. These conditions can cause
measurement errors which are called electrical or mechanical runout.
Avoid surface irregularities such as hammer marks, scratches, shoulders,
projections, holes, or keyways. Bently Nevada recommends 0.41 to 0.76
micrometres (16 to 30 microinches) shaft surface finish because cast or rough
surfaces produce small amounts of mechanical runout. American Petroleum
Institute (API) 670 recommends a maximum residual magnetism of 0.5 millitesla
(5.0 gauss). In addition, any type of plating (including chrome) which has a
nonuniform thickness may result in electrical or mechanical runout. The following
application notes describe various techniques for reducing or eliminating
electrical and mechanical runout:
• "Glitch": Definition of and Methods for Correction, including Shaft
Burnishing to Remove Electrical Runout. (Application note AN002)
• API 670, second edition, Section 4.1.2: Machine Shaft Requirements for
Electrical and Mechanical runout.

2.1.4 Verifying the Mounting Location

Since the transducer operates by using a magnetic field at the tip, design the
transducer mounts with adequate side clearance and separation so that nothing
interferes with the magnetic field.

2.1.4.1 Side Clearance

Although most of the magnetic field radiates in an axial direction from the tip of
the transducer, some of the field radiates from the sides of the tip. Therefore,
conductive material at the side of the transducer affects the transducer scale
factor. To reduce this effect, verify that the conductive material on the sides of
the transducer is no closer than the minimum distances shown in Figure 2-5
designated as "B". If the brackets or machine parts are too close to the
transducer tip, use a counterbore to obtain the required clearance. Appendix E

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Differential Expansion Transducer System Operation Manual
shows the typical effect of insufficient flat surface side clearance on the 25mm
Differential Expansion Transducer. This effect varies in actual applications due to
surface material and mounting configurations.

B = 38mm (1.5 in) minimum

C = 22.2mm (0.875 in) minimum

2.1.5 Transducer Separation

The electromagnetic fields of transducer tips mounted too closely together will
cross-couple, causing a small amplitude ac signal to be superimposed on the
transducer outputs. To prevent cross-coupling mount the transducers so that the
distance between the tips is at least as large as that shown in Figure 2-6.

A = 102 mm (4.0 in) Minimum

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 Section 2 - Installation
2.2 Mounting the Transducer
Mount the transducer in the machine by installing the mounting bracket, checking
the mounting holes, and installing the transducer in the mounting bracket.

2.2.1 Installing the Mounting Bracket

WARNING
Contact with rotating machinery causes severe
injury. Exercise extreme care when working
around rotating machinery.
The brackets and other structural members used to mount the transducer must
be rigid. The resonant frequency of the mounts should be at least 10 times the
machine running speed to reduce false vibration signals.
A smooth body transducer mounting clamp is shipped with each smooth body
transducer. The user must supply the mount for threaded body transducer
applications. Attach the mount to the machine case either directly or by means
of a user supplied bracket.
The transducer mount should be installed so the transducer will be perpendicular
to the observed surface or the transducer range, scale factor, and linearity may
be affected. Errors caused by an incorrect mounting angle are usually small if the
transducer is mounted within ±5° of perpendicular.

2.2.2 Checking the Mounting Holes

CAUTION
Metal filings can damage the internal components
of the machine. Remove all of the metal filings
from inside of the machine.
Be sure the mounting holes for the transducer are free of foreign material. If you
cannot screw the transducer into the mounting hole easily, use an appropriate
tap to clean the threads.

2.2.3 Installing the Transducer in the Mounting Bracket

CAUTION
Threading the transducer without turning the cable
may damage the transducer. When installing a
transducer with a long integral cable, be sure the
cable turns with the transducer.

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Differential Expansion Transducer System Operation Manual
Install the transducer into its mounting bracket as shown in Figure 2-7. Do not
tighten the lock nut on the threaded transducer or the clamping bolt on the
smooth body transducer until after checking the installation.

2.3 Checking the Transducer Installation

CAUTION
Transducer location and observed surface
variations can affect the linearity and range of the
transducer. Create a transducer response curve
for each installation to ensure proper operation of
the system.
Before proceeding with the installation, check the installation by making a
transducer response curve for the installed transducer. Use the curve to
• verify that the installation has not changed the sensitivity of the system
• verify that the linear range of the system spans the predicted mechanical
movement of the shaft
• determine the optimum gap setting
The following steps show how to make a transducer response curve.

CAUTION

Use of a current limited power supply is required;

otherwise accidental reverse connection may
result in permanent damage to the transducer.

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 Section 2 - Installation
Step 1—Connect the test equipment as shown in Figure 2-8. If an adjustable current
limit is available on the power supply, set the limit between 25 and 45 mA.

Step 2—Place a gauge or shim block set to 25 mils between the transducer tip
and the target. Slide or thread the transducer until it lightly touches the block.
Excessive contact force can damage the transducer. Be sure that the transducer
mount does not cover any part of the transducer tip or the readings will be in
error.

Step 3—Remove the block and record the voltage at the output of the
transducer.

Step 4—Increase the gap in 50 mil increments and record the output voltage
until the gap is 525 mils.

Step 5—Plot the voltage reading versus gap as shown in Figure 2-9.
Step 6—Include information on the mechanical movement of the shaft on this
graph as shown in Figure 2-9.

Step 7—Save a copy of this curve in a secure place for future reference.

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Differential Expansion Transducer System Operation Manual

2.3.1 Gapping the Transducer

WARNING

Gapping the transducer while the machine is

running could damage the transducer as well as
the machine. Gap the transducer when the
machine is stopped so that the transducer can be
easily placed at a known position relative to the
observed surface.
Use the transducer response curve from the previous section to determine the
correct gap for the transducer. You can use either a gauge method or electrical
method to gap the transducer.

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 Section 2 - Installation
Gauge Method

Place a gauge or shim block that is as wide as the desired mechanical gap
between the transducer tip and the target. Slide or thread the transducer until it
lightly touches the block.

Electrical method

Connect the transducer as shown in Figure 2-8. Slide or thread the transducer
into the mount until the proper output voltage is observed.
WARNING

Loose parts in the machine can cause damage or

injury. Secure all parts that can loosen over time
with steel safety wire and a thread locking
compound.

Tighten the lock nut, clamp, or other retainer. Use a thread locking compound
(Loctite or equivalent) and safety wire to prevent parts from loosening.

2.3.1.1 Connecting the Transducer Wiring

After the transducer is mounted in the machine, route the wiring back to the
monitor by:
• securing the cable inside the machine
• terminating the transducer cable and connecting it to the field wiring
• routing the field wiring back to the monitor

Secure the Cable Inside the Machine

Since the transducer cable mounted inside the machine may be worn or
damaged by windage (circulating air inside the turbine), secure the cable by using
conduit. If conduit is unavailable, use armored cable and securely fasten the
armor to a rigid surface. The use of unprotected cable (no conduit or armor) is
not recommended. If unprotected cable must be used, securely fasten the cable
to a rigid surface using non-metallic tie downs such as teflon cable ties. Other
cable holding devices can be used, but be sure that the teflon jacket on the cable
does not cold flow and short to any conductive material. A short could introduce
ground loops into the system.

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Differential Expansion Transducer System Operation Manual
If the transducer is mounted in a vacuum, use a low pressure seal (Bently Nevada
part number 43501) to seal around the transducer cable where it exits the
machine.

Terminate the Cable

Most installations use some form of terminal housing near the machine to splice
the transducer cable into the transducer field wiring that runs back to the monitor
as shown in Figure 2-10. Be sure to label the cable at each junction using the
extra shrink tubing shipped with each transducer.

Route Wiring back to the Monitor

You must supply the field wiring from the transducer to the monitors unless you
specifically request Bently Nevada Corporation to provide it. The transducer
output signal and input power are transmitted between the transducer and the
monitor through a 3 conductor twisted shielded wire. Appendix B lists acceptable
interconnect cables.
Protect all cables against mechanical damage by using conduit or armor. A
terminal housing (Bently Nevada part number 106769) may be used to protect
the cable where it exits the machine and enters the conduit. Refer to Appendix B.
Ground the shield of the field wiring cable only at the monitor end. Connect all
the shields of the field wiring in the same rack to the same earth ground to avoid
ground loops.
For more information on grounding and isolation, refer to the Bently Nevada
application note "Guidelines for grounding (Earthing) Bently Nevada Rotating
Machinery Information Systems" (Application Note AN013).

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 Section 2 - Installation
2.4 Common Transducer Installation Errors
The following table lists common installation errors. Review these errors to avoid
repeating them during your installation.
TYPE OF ERROR RESULT OF ERROR
Measurements for installing the transducer The transducer mounting must be
are not accurate enough to allow for a redesigned.
proper fit.
The transducer is mounted over chrome The readings from the transducer are
plating, coupling hubs, or shrink on collars. erratic.
A transducer is mounted in a bracket or The monitor gives a false "OK" indication.
housing, but does not extend through the The monitor indicates the transducer is
hole. observing the shaft when it is not.
The transducer is mounted on brackets that Resonance causes the transducer to vibrate
are not rigid enough. at a high amplitude. This can add an AC
signal on top of the DC gap signal.
The transducer lead is not sufficiently The cable may be damaged during normal
protected from mechanical hazards. work around the machine.
The conduit for the transducer cable is not The terminal housing becomes filled with
sealed adequately. lube oil or condensation forms inside the
housing. This can cause erratic or false
transducer readings.
The transducer is screwed into the mount The transducer cable is broken off.
by using the transducer cable.
The transducer cable remains connected to The transducer cable becomes twisted and
a fixed object while threading the breaks.
transducer into its mount.
Too much torque (>163 N m (120 ft-lb) ) is The transducer case is broken.
applied to the transducer case during
installation.
Many transducer cables are routed through Transducers are connected to the wrong
a common conduit with no identification. monitors.
The transducer cable is routed through a The output signal of the transducer will
common conduit or wire tray with other contain noise coupled from the other
cables carrying high voltage levels, or cables.
voltages that change rapidly.
Cables on internally mounted transducers Aerodynamic forces break the cable.
are not tied down.
Transducers are mounted too close The electromagnetic fields of transducer
together (see Figure 2-6). tips cross-couple, causing a small amplitude
ac signal to be superimposed on the
outputs.
Transducer is observing a collar that is too The transducer range and linearity is
small (see Figure 2-4). reduced.

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Differential Expansion Transducer System Operation Manual

3. Maintenance
This section contains a list of recommended maintenance equipment and
instructions for storing, testing, and troubleshooting the transducer system.
Performing any maintenance other than that which is specified in this section
may void the warranty for the transducer system.

3.1 Recommended Maintenance Equipment

The following table contains recommended maintenance equipment for the
verification and troubleshooting procedures. If this equipment is not available,
you can use equivalent instruments.
Maintenance Equipment Recommended Equipment
Digital Multimeter Tektronix Model DM2510 4½ Digit DMM

Power Supply Tektronix Model PS281

Micrometer Bently Nevada Part Number 88249-01-01

10K Ω Resistor

3.2 Storing the System

The 25mm Differential Expansion Transducer is shipped as a system to be
installed by the user. If no shipping damage is apparent and the system is not
going to be installed immediately, return the components to the shipping
containers and reseal them until ready for installation.
Store the containers in a cool, dry location which is free of corrosive substances.
Appendix D contains environmental specifications for each component.

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 Section 3 - Maintenance

3.3 Verification Test

Use this test procedure to verify the operation of your 25mm Differential
Expansion Transducer System. Perform the verification test if you change
transducers or use target material other than 4140 steel.

Step 1—Connect the test equipment as shown in 1. Be sure that your transducer
system is properly connected. If an adjustable current limit is available on your
power supply, set it between 25 and 45 mA.

Step 2—Set the spindle on the micrometer to zero.

Step 3—Insert the transducer into the transducer holder so that the transducer tip
lightly contacts the target. Clamp the transducer in this position.

Step 4—Adjust the gap to 25 mils and record the output voltage.
Step 5—Increase the gap in 50 mil increments and record the output voltage at
each gap.

Step 6—Calculate the system average scale factor (ASF). Subtract the voltage at
the 525 mils gap from the voltage at the 25 mils gap and divide by 500.

The calculated ASF for the system should be within 19.0 to 21.0 mV/mil for 4140.
Note:Special target materials or unusual target geometries can cause increased
error. The best test for the system is to run a transducer response curve in place
on the machine and verify that it meets the needs of the application. See
Checking the Transducer Installation on page 14.

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Differential Expansion Transducer System Operation Manual

Figure 3-1. Equipment Setup for Verification Test

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 Section 3 - Maintenance
An example should help clarify ASF calculations. Suppose you have taken the
following measurements.
Micrometer Multimeter
Display Display
(mils) (V)
25 -1.490
75 -2.520
125 -3.535
175 -4.561
225 -5.575
275 -6.600
325 -7.630
375 -8.649
425 -9.655
475 -10.670
525 -11.690
575 -12.720

Calculate the ASF like this:

- 1.490 - (-11.690)
ASF =
500

10.200 V
ASF = = 20.4 mV/mil
500 mils
This is within 19 to 21 mV/mil, so the transducer is functioning properly.
If the calculated ASF is out of tolerance, the system is not operating properly. If
you can not locate and correct the problem, contact your nearest Bently Nevada
office for assistance.

3.4 Troubleshooting
Use the following troubleshooting procedure to isolate and correct faults on
installed transducer systems. Before beginning this procedure, be sure the
system has been installed correctly and all connectors have been properly
secured.
When a malfunction occurs, select the appropriate fault indication and step
through the probable causes to isolate and correct the fault. Use a digital
multimeter to measure voltage and resistance where specified.

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Differential Expansion Transducer System Operation Manual
Please return faulty system components to a Bently Nevada Corporation office.

Fault #1 The voltage between the 25mm Differential

Expansion Transducer COM and Vt terminals
is not within the range of -26 Vdc to -17.5
Vdc.

Probable Cause

1. Faulty power source

2. Faulty wiring between the power source
and the transducer.
3. Faulty transducer

Isolation and Correction

Disconnect the output wiring at the power

source and measure the output voltage at the
power source.
Reconnect the wiring at the power source and
disconnect the wiring at the transducer.
Measure the voltage at the wire terminals that
connect to the transducer.

Fault #2 The voltage between the 25mm Differential

Expansion Transducer OUTPUT and COM
terminals remains at 0.0 Vdc.

Probable Cause 1. Incorrect supply voltage

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 Section 3 - Maintenance
2. Short circuit in the instrument connected to
the transducer OUT wire
3. Short circuit in the field wiring
4. Faulty transducer

Isolation and Correction Be sure that fault condition #1 does not exist.
Disconnect the output wire at the instrument
and measure the transducer output voltage
between the transducer OUT and COM wires
at the wire terminals which connect to the
instrument.
Reconnect the output wire at the instrument
and disconnect the wiring at the transducer.
Measure the transducer output voltage
between the transducer OUT and COM wires.

Fault #3 The voltage between the transducer OUT and

COM wires remains between -1.0 and 0.0 Vdc
but not equal to 0.0 Vdc.

Probable Cause 1. Incorrect supply voltage

2. Incorrect gap
3. Faulty Transducer

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Differential Expansion Transducer System Operation Manual
Isolation and Correction Be sure that fault condition #1 does not exist.
Measure the gap between the transducer tip
and the target.

Fault #4 The voltage between the 25mm Differential

Expansion Transducer OUT and COM wires
remains identical to the voltage between the
COM and Vt terminals.

Probable Cause 1. Incorrect supply voltage

2. Short circuit in the field wiring
3. Faulty transducer

Isolation and Solution Be sure that fault condition #1 does not exist.

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 Section 3 - Maintenance
Remove the wiring from the transducer OUT
wire and measure the voltage between the
transducer OUT and COM wires.

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Differential Expansion Transducer System Operation Manual

4. Glossary
The following terms are used throughout this manual. Any other definition of
these terms does not apply to this manual.
ASF Average Scale Factor. The slope of the transducer's
calibration curve over the entire calibration range.
ASF is measured in mV/mil or V/mm. See Sensitivity.
Cold Flow A change in dimension or distortion caused by the
sustained application of force. This force can cause
the Teflon insulation on wires to move, expose the
inner conductor, and allow the wire to short.
DSL Deviation from Straight Line. A measure of how
close the transducer's calibration curve is to a
straight line. The straight line is centered to provide
equal positive and negative errors. DSL error is
measured in mils or mm.
Electrical Runout A noise component in the output signal of a
proximity probe transducer system resulting from
non-uniform electrical conductivity and magnetic
permeability properties of the observed material.
Also caused by local (spot) magnetic fields on the
circumference of the shaft surface. A change in the
Proximitor® output signal which does not result from
a probe gap change (dynamic motion change or
change in average shaft position). The error repeats
exactly with each shaft revolution. See Mechanical
Runout.
Glitch See Electrical Runout and Mechanical Runout.
Hertz (Hz) A unit of frequency measurement in cycles per
second.
ISF Incremental Scale Factor. The slope of the
transducer's calibration curve over a specified
increment. ISF is measured in mV/mil or V/mm. Also
referred to as the derivatives. See Sensitivity.

28
 Section 4 - Glossary
Keyphasor Transducer Transducer which produces a once-per-shaft-turn
voltage pulse, called the Keyphasor signal. This
signal is used primarily to measure shaft rotative
speed and as a reference for measuring vibration
phase lag angle. It is an essential element in
measuring rotor slow roll bow/runout information.
The Keyphasor® transducer is typically a proximity
probe (recommended for permanent installations in
which the probe observes a physical gap change
event), an optical pickup (used for temporary
installations in which the pickup observes a change
in reflectivity event) or a magnetic pickup.
Mechanical Runout A source of error on the output signal of a proximity
probe transducer system. A probe gap change
which does not result from either a shaft centerline
position change or shaft dynamic motion. Common
sources include out of round shafts, scratches, chain
marks, dents, rust or other conductive build up on
the shaft, stencil marks, flat spots, and engravings.
See Electrical Runout.
mMetre A unit of length equal to 3.2808 ft.
Mil A unit of length or displacement equal to 0.001 inch.
One mil equals 25.4 micrometres or 0.0254 mm.
mmMillimetre A unit of length or displacement equal to 0.001
metre. One mm equals 0.03937 inches.
Noise Any component of a transducer output signal which
does not represent the variable intended to be
measured.
Observed Surface The surface from which the probe is gapped. This
surface is also the surface being monitored for gap
changes by the probe.
PPSPolyphenylene sulfide The thermoplastic material used to provide a
protective covering for the probe tip.
Proximity Probe A noncontacting device which measures the
displacement motion and position of an observed
surface relative to the probe mounting location.
Typically, proximity probes used for rotating
machinery measurements operate on the eddy
current principle and measure shaft displacement
motion and position relative to the machine
bearing(s) or housing.

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Differential Expansion Transducer System Operation Manual
Sensitivity The ratio of the response or change induced in the
output to a stimulus or change in the input. The
sensitivity for a 25mm Differential Expansion
transducer is 788 V/mm (20 mV/mil). See ASF and
ISF.
NOTE: For more definitions of terms used in rotating machinery, refer to the Bently
Nevada Glossary (BNC Publication L-1014).

30
 Section 5 - Appendix A – Ordering Information

5. Appendix A Ordering Information

Appendix A contains ordering information for the 25mm Differential Expansion
Transducer System including instructions for receiving and inspecting your order
and part numbers for each system component.

5.1 Receiving and Inspecting Your Order

When you receive your order, carefully remove all equipment from the shipping
containers and inspect each item for shipping damage. If shipping damage is
apparent, file a claim with the carrier and submit a copy to Bently Nevada
Corporation. Include the part numbers and serial numbers of the damaged items
on all correspondence.

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Differential Expansion Transducer System Operation Manual

5.2 Ordering Information

Standard Mount 1 1/4-12 Case
Part Number: 102241 – AXX – BXX – CXX - DXX
A: Unthreaded Length
Increments of 0.1 inch.
Examples:
00 0.0 inch (minimum length)
84 8.4 inches (maximum length)
Note: The unthreaded length must be at least 1.4 inches less than the overall case
length.
B: Overall Case Length
Increments of 0.1 inch.
Examples:
20 2.0 inches (minimum length)
98 9.8 inches (maximum length)
C: Cable Length
50 5.0 metres
51 5.0 metres with connector
90 9.0 metres
91 9.0 metres with connector
D: Armor
00 No armor
01 With armor

32
 Section 5 - Appendix A – Ordering Information
Standard Mount M30x2 Case
Part Number: 102242 – AXX – BXX – CXX - DXX
A: Unthreaded Length
Increments of 10 mm.
Examples:
00 0 mm (minimum length)
22 220 mm (maximum length)
Note: The unthreaded length must be at least 30 mm less than the overall case
length.
B: Overall Case Length
Increments of 10 mm.
Examples:
05 50 mm (minimum length)
25 250 mm (maximum length)
C: Cable Length
50 5.0 metres
51 5.0 metres with connector
90 9.0 metres
91 9.0 metres with connector
D: Armor
00 No armor
01 With armor

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Differential Expansion Transducer System Operation Manual
Smooth Body, Rear Exit
Part Number 102243 – AXX – BXX - CXX
A: Overall Case Length
Increments of 0.1 inches.
Examples:
20 2.0 inches (minimum length)
98 9.8 inches (maximum length)
B: Cable Length
50 5.0 metres
51 5.0 metres with connector
90 9.0 metres
91 9.0 metres with connector
C: Armor
00 No armor
01 With armor

34
 Section 5 - Appendix A – Ordering Information
Smooth Body, Side Exit
Part Number 102244 – AXX – BXX - CXX
A: Overall Case Length
Increments of 0.1 inches.
Examples:
20 2.0 inches (minimum length)
98 9.8 inches (maximum length)
B: Cable Length
50 5.0 metres
51 5.0 metres with connector
90 9.0 metres
91 9.0 metres with connector

C: Armor
00 No armor
01 With armor

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Differential Expansion Transducer System Operation Manual

6. Appendix B Optional Accessories

6.1 Housings

Water and Corrosion-resistant Housing

Basic BNC Maximum

Catalog Proximitor®
Number Capacity

24584 2 Housing constructed of fiberglass

24585 4
24586 6

Water-resistant Housing

Basic BNC Maximum

Catalog Proximitor®
Number Capacity
Housing constructed of 304L SST
72381 2
72382 4
72383 6

Explosion-proof Housing

Basic BNC Maximum

Catalog Proximitor® Housing is Killark GR Series
Number Capacity

72341 2
72342 4

36
 Section 6 - Appendix B – Optional Accessories

6.2 Transducer Accessories

Terminal Housing
Part Number: 106769-AA
(-02 version shown)

Junction Boxes

Main Body and Blank Cover Extension (optional)

Catalog Number: 03818016 Catalog Number: 03818022

Catalog Conduit
Number Size

03818065 1/2 inch NPT

03818066 3/4 inch NPT

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Differential Expansion Transducer System Operation Manual
Explosion-proof Fittings

Catalog Conduit
Number Size
03818055 1/2 inch
03818056 3/4 inch
03818057 1 inch
03818058 1-1/4 inch
Sealtite Flexible Conduit

Catalog Assembly
Number Type
14847 1/2 inch
14848 3/4 inch
Adapter
Catalog External
Number Thread

4190-59 3/4 inch NPT

Catalog Number: 43501-HP

Can be used for up to two
25mm transducer cables.
Use punch kit below
Low Pressure Cable Seal Accessories
Catalog Number Accessory
04490104 Punch kit for solid grommet (Use punch #2)
43574-00 Replacement solid grommet holds up to 2 cables
43575-00 Replacement solid washer (2 required per cable seal)

38
 Section 7 - Index
Interconnect Cable

Catalog Part
Number Description

02173008 22 AWG 3 cond. twisted, braided shield

02173006 18 AWG 3 cond. twisted, braided shield
02120015 18 AWG 3 cond. twisted, drain wire, braided shield
Terminal Mounting Block

Catalog Part
Number Description

103537-01 Terminal Block, will mount in place of any

Proximitor®.
Micrometer

88249-01-01 Micrometer compatible with the 25mm

Differential Expansion Transducer
(Units are in mils)

105825-01 Field Connector Kit. Includes extra shrink tubing, ring lugs and a
terminal block for terminating the 25mm Differential Expansion
Transducer cable.

39
Differential Expansion Transducer System Operation Manual

7. Appendix C Mechanical Drawings

40
Section 7 - Index

41
Differential Expansion Transducer System Operation Manual

42
Section 7 - Index

43
Differential Expansion Transducer System Operation Manual

44
 Section 7 - Index

8. Appendix D Specifications
Unless otherwise noted, the following specifications apply at 22 °C ± 4.4 °C (72 °F
± 8 °F) using a target of AISI 4140 steel and test equipment with accuracy as
specified by Bently Nevada Specification 150980.

NOTE: Operation outside the specified limits will result in false readings or loss
of machine monitoring.

The linear range is defined as the 12.7 mm (500 mil) range from 2.54 mm (100
mils) below -3.5 Vdc to 10.16 mm (400 mils) above -3.5 Vdc. This range is
approximately equivalent to a linear range from 0.635 mm (25 mils) to 13.34 mm
(525 mils).

Electrical
Average scale factor (ASF)
788 ± 15.8 mV/mm ( 20 ± 0.4 mV/mil )
Deviation from a straight line (DSL)
Within ± 0.178 mm ( + 7 mils )
Deviation or error from a straight line is the difference between the actual
and theoretical output for a transducer. To calculate DSL, generate an
output voltage versus gap curve over the linear range of the transducer
under test. Next, determine the theoretical straight line that best fits the
actual curve and has a slope equal to the ideal scale factor. To determine
the DSL for each gap reading, convert the voltage difference to units of
distance by multiplying by the ideal scale factor.
Mechanical Gap Output will be -3.5 Vdc at a gap of 3.175 + 0.203 mm
(125 + 8 mils )
Supply sensitivity Less than 2 mV change in output per volt change at
input
Supply voltage range -17.5 to -26 Vdc
Current draw 12 mA maximum with 10 kΩ load to common
Output resistance 50 Ω

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Differential Expansion Transducer System Operation Manual
Output load All specifications with a 10 kΩ, 0.01 µF parallel load
Calibrated using 10 kΩ load only

Incorrect field wiring When used below 71°C (160°F) with a 3300 Series
monitor, the 25mm Differential Expansion
Transducer can be wired wrong in any manner, for
an indefinite period of time, without damage.
Short circuit duration Output may be shorted to common continuously for
ambient temperatures below 71°C (160°F)
Typical Frequency response
+0%, -5% from 0 to 800 Hz (0 to 48,000 cpm)
+0, -3dB from 0 to 2000 Hz (0 to 120,000 cpm)
Frequency response due to a capacitive load
See Figure E-5.
Output noise Less than 50 mV pp, plus any high frequency noise
present on the supply when connected to a monitor
with a 0.01uF capacitor on the transducer output.

Recalibration to materials other than 4140

The unique digital calibration method used in the
25mm Differential Expansion Transducer allows
recalibration to most metals with little reduction in
room temperature performance. This flexibility
requires that recalibration be done by Bently Nevada
Corporation. Contact your nearest Bently Nevada
Corporation representative for assistance in
obtaining calibration for custom materials.
Case to cable isolation resistance
Capable of withstanding a minimum of 500 Vac at 60
Hz between transducer case and electrical circuits
with less than 1 mA current flow

Environmental
Temperature
Storage -35 to +125°C (-31 to +257°F)
Operating -35 to +125°C (-31 to +257°F)
Relative humidity 100% condensing RH
46
 Section 7 - Index
Mechanical
Materials
wire insulation Fluorinated ethylene-propylene (FEP)
tip Polyphenylene sulfide (PPS)
case 303 stainless steel (SST)
armor (if used) Flexible 302 SST with TEFZEL 280 outer jacket

shrink tubing FEP

Case torque (maximum rated)
1.25-12 or M30x2 cases 163 N⋅m (120 ft-lb) with all lock nut
threads engaged
Tensile strength (maximum rated)
tip to cable 334 N (75 lb)
case to armor
(if applicable) 223 N (50 lb)
Minimum bend radius 25 mm (1 in)
Mass (weight) 0.9 to 2.7 kg (31 to 95 oz) (includes jam
nut and 9 metres of cable)
Chemical Compatibility
Transducer function is not affected by direct contact with the following
substances:
Air
Ammonium hydroxide
Lube oil
Water
The transducer is compatible with many types of harsh chemical
environments, but certain environments can damage the transducer. It is
impractical to list compatible and incompatible chemicals for the
transducer, because compatibility depends on factors such as temperature,
chemical concentration, and chemical combinations. Before installing the
transducer, you need to determine whether the transducer is compatible
with the installation environment. To assist you in determining compatibility,

47
Differential Expansion Transducer System Operation Manual
the exposed materials of the transducer (not including the connector) are
listed below.
Transducer
Component Material

Case 303 SST

Tip PPS

O-rings Viton

Cable Insulation FEP

48
 Section 8 - Appendix E Sensitivity Curves

9. Appendix E Sensitivity Curves

49
Differential Expansion Transducer System Operation Manual

50
Section 8 - Appendix E Sensitivity Curves

mm (inches)

51
Differential Expansion Transducer System Operation Manual

A B

mm(inches)

52
Section 8 - Appendix E Sensitivity Curves

53
Differential Expansion Transducer System Operation Manual

54
 Section 9 - Index

10. Index
A Capacitance
Response to a capacitive load.....................D-2
Accessories .................................................................. B-1 Role in operation..................................................1-3
AISI series steels ........................................................ 2-8 Case
Angle, required mounting angle......................2-12 Block diagram .......................................................1-3
Application notes .......................................... 2-8, 2-19 Ordering information........................................ A-2
Applications Specifications .......................................................D-3
High pressure applications ............................ 2-5 System components ..........................................1-1
How to measure differential Chemical compatibility .................................2-6, D-3
expansion..................................................... 2-2 Chrome plating ...........................................................2-8
Inappropriate applications............................. 2-2 Circuitry
Approvals ......................................................................A-4 Basic operation.....................................................1-3
Armor Option...............................................................D-3 Block diagram .......................................................1-3
ASF (see average scale factor) Clearance ...................................................................2-10
Average scale factor (ASF) Cold flow .............................................. 2-6, Glossary-1
Definition..................................................Glossary-1 Collar height variations
How to calculate ................................................. 3-2 Required target size ...........................................2-7
Sample calculation ............................................ 3-4 Sensitivity curve ...................................................E-4
Worst case specification.................................D-1 Common installation errors...............................2-20
Complimentary input differential
expansion .....................................................2-3
B
Conductive surface
Bently Nevada application notes .......... 2-8, 2-19
Evaluating the observed surface.................2-7
Block diagram............................................................. 1-3
Recalibration for other surfaces .................D-2
Bracket, installing the mounting
bracket.........................................................2-12 Theory of operation............................................1-3
Conduit........................................................................... B-3
Installation considerations ..........................2-18
C
Ordering information........................................ B-3
Cable
Configurations, mounting......................................2-3
Cable construction............................................. 1-2
Connector
Connecting transducer wiring....................2-18
Option....................................................................... A-4
Mechanical drawings........................................C-1
Counterboring, when required.........................2-10
Minimum bend radius.......................................D-3
Cross coupling
Ordering information ........................................A-2
Required probe separation..........................2-11
Part numbers ........................................................ B-4
Current draw...............................................................D-1
Result of incorrect field wiring......................D-1
Curve
Terminating the cable at the
machine case...........................................2-19 Making a response curve .............................2-14
Cable Seal ..................................................................... B-3 Sensitivity curves.................................................E-1

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Differential Expansion Transducer System Operation Manual

D G
Deviation from Straight Line (DSL)............................ Gap
Glossary-1, D-1 Gapping the transducer................................ 2-17
Diagnostics Mechanical gap specification ...................... D-1
Common installation errors.........................2-20 Gauge method, probe gapping....................... 2-17
Cross coupling ...................................................2-11 Glitch 2-8, Glossary-1
Plated surfaces.....................................................2-8 Grounding .................................................................. 2-19
Troubleshooting procedure............................3-4
Using a response curve.................................2-14 H
Verification test ....................................................3-2 Hazardous Area Approvals...................................A-4
Diagrams High pressure applications...................................2-5
Block diagram .......................................................1-3 Housing
Mounting configurations .................................2-3 Transducer accessories ...................................B-1
Typical response curve..................................2-16 Using terminal housing near the
Differential expansion machine...................................................... 2-19
How to measure ..................................................2-2
Mounting configurations .................................2-3 I
Incremental Scale Factor (ISF)............. Glossary-1
E Input Power................................................................. D-1
Eddy currents, theory of operation ...................1-3 Inspecting and receiving .......................................A-1
Electrical method, probe gapping ..................2-17 Installation
Electrical runout, installation Checking environmental conditions ..........2-5
consideration .................... 2-8, Glossary-1 Checking the installation .................................. 2-14
Environmental conditions Checking the mounting holes ........................ 2-13
Checking environmental conditions ..........2-5 Common installation errors ............................ 2-20
Environmental specifications .......................D-2 Connecting the transducer wiring ............... 2-18
Equipment setup Evaluating the observed surface.....................2-7
for transducer response curve ..................2-14 Gapping the transducer.................................... 2-17
for verification test..............................................3-3 General approach...................................................2-1
Errors Installing the mounting bracket.................... 2-12
Common installation errors.........................2-20 Installing transducer in bracket .................... 2-13
Deviation from straight line (DSL) ...............D-1 Mounting configurations .....................................2-3
Planning the installation ......................................2-1
F Securing the cable............................................... 2-18
Fiberglass housing ................................................... B-1 Verifying the mounting location ................... 2-10
Field Wiring ..................................................................D-2 ISF (see incremental scale factor)
Frequency response
Specification .........................................................D-2 J
Typical frequency response at Junction Box ....................................................................B-2
mid-gap .........................................................E-6

56
 Section 9 - Index
K Mounting configurations
Keyphasor measurements, inappropriate for measuring differential expansion ........2-3
application ....................................................... 2-2 Mechanical drawings ....................................... C-3
Keyphasor transducer .................................Glossary-1 Ordering options................................................. A-4

L N
Leakage of gasses and liquids................................ 2-5 Noise
Load, ouput load .......................................................D-1 Definition .................................................Glossary-2
Specification .........................................................D-2
M
Magnetic field O
Minimum probe separation .........................2-10 Observed material
Theory of operation ........................................... 1-3 Affect on response curve.................................2-8
Maintenance ............................................................... 3-1 Observed surface, definition ................Glossary-2
Maintenance Equipment....................................... 3-1 Operating temperature ..........................................2-5
Malfunctions Operation.......................................................................1-3
Common installation errors.........................2-20 Ordering Information.............................................. A-1
Cross coupling....................................................2-11 Output
Plated surfaces .................................................... 2-8 Load ..........................................................................D-1
Troubleshooting procedure ........................... 3-4 Noise specification.............................................D-2
Using a response curve .................................2-14 Resistance..............................................................D-1
Mass, specification ...................................................D-3
Material P
Material used in system components.......D-3 Part numbers.............................................................. A-2
Observed shaft material.................................. 2-8 Planning the installation.........................................2-1
Mechanical drawings..............................................C-1 Plated surfaces ...........................................................2-8
Mechanical method, probe gapping .............2-17 Power supply voltage
Mechanical runout, installation Range .......................................................................D-1
consideration..................... 2-8, Glossary-2
Sensitivity to supply voltage...........................E-5
Mechanical specifications ....................................D-3
Troubleshooting incorrect voltage..............3-5
Micrometer................................................................... 3-1
Pressure sealing
for verification test ............................................. 3-3
Cable seal accessories..................................... B-3
Part number .......................................................... B-4
Installation considerations .............................2-5
Moisture sealing ........................................................ 2-6
Probe tip...................................................................2-5
Monitor, routing wiring to the monitor .........2-19
Probe gap
Mounting
Gapping the transducer................................2-17
Configurations...................................................... 2-3
Mechanical gap specification.......................D-1
Installing the mounting bracket ................2-12
Probe tip
Resonant frequency of mounting
Definition .................................................Glossary-2
bracket.........................................................2-12
Gapping the transducer................................2-17
Verifying the mounting location................2-10
Pressure sealing...................................................2-5
Mounting angle........................................................2-12
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Differential Expansion Transducer System Operation Manual
Required separation........................................2-11 Separation, required transducer
Required side clearance................................2-10 separation ................................................. 2-11
Theory of operation............................................1-3 Setup
Probe, Installation considerations for transducer response curve 2-14
Chemical compatibility .....................................2-6 for verification test 3-3
Pressure sealing...................................................2-5 Shaft
Surface considerations.....................................2-7 Material 2-8
Problems Shaft surface finish 2-8
Common installation errors.........................2-20 Short circuit duration D-2
Cross coupling ...................................................2-11 Shrink Tubing D-3
Plated surfaces.....................................................2-8 Side clearance
Troubleshooting procedure............................3-4 Effect of side clearance E-3
Using a response curve.................................2-14 Installation consideration 2-10
Protective Armor .......................................................D-3 Side exit mounting configuration A-4
Proximity probe, definition ....................Glossary-2 Single input differential expansion 2-3
Smooth body transducer
R Installation 2-12
Mechanical drawings C-3
Ramp differential expansion................................2-4
Ordering information A-4
Rear exit mounting configuration..................... A-4
Specifications D-1
Receiving and inspecting...................................... A-1
Standard body mount
Residual magnetism, Effect on runout............2-8
Mechanical drawings C-1
Resistance
Mounting the transducer 2-13
Case to cable isolation resistance..............D-2
Ordering information A-2
Output resistance...............................................D-1
Securing the transducer 2-17
Resonant frequency
Steels 2-8
of mounting bracket .......................................2-12
Storing the System 3-1
Response curve
Supply voltage
Affect of observed material............................2-8
Range D-1
How to plot ..........................................................2-14
Sensitivity to supply voltage E-5
Typical response curve..................................2-16
Troubleshooting incorrect power
Typical temperature response curve................
supply voltage 3-5
E-1, E-2
Surface
Runout, installation consideration ....................2-8
Considerations 2-7
Definition Glossary-2
S Effect of plated surfaces on runout 2-8
Sealing Evaluating the observed surface 2-7
Moisture sealing...................................................2-6 Finish 2-8
Pressure sealing...................................... 2-5, 2-18 Recalibration to other surfaces D-2
Sealing accessories........................................... B-3 Theory of operation 1-3
Sensitivity Curves.......................................................E-1 System
Sensitivity, definition.................................Glossary-2 Components of 1-1

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 Section 9 - Index
Features 1-2 Minimum bend radius ......................................D-3
Inappropriate applications 2-2 Part numbers........................................................ B-4
Material used in system components D-3 Terminating the cable at the
Recalibration to other surfaces D-2 machine case...........................................2-19
Receiving and inspecting A-1 Transducer case
Storing the system 3-1 Block diagram .......................................................1-3
Theory of operation 1-3 Ordering information........................................ A-2
Troubleshooting the system 3-4 Specifications .......................................................D-3
Verification test 3-2 System components ..........................................1-1
Verifying the performance 2-14 Transducer installation
Checking environmental conditions ..........2-5
T Checking the installation ..............................2-14
Checking the mounting holes ....................2-13
Target material
Common installation errors.........................2-20
Affect on response curve 2-8, 3-2
Connecting the transducer wiring ...........2-18
Recalibration to other surfaces D-2
Evaluating the observed surface.................2-7
Target size
Gapping the transducer................................2-17
Effect of collar height variations E-4
General approach ...............................................2-1
Minimum requirement 2-7
Installing the mounting bracket................2-12
Teflon insulation on the cable 2-6
Installing transducer in bracket ................2-13
Temperature
Mounting configurations .................................2-3
Operating temperature 2-5
Planning the installation ..................................2-1
Storage and operating specifications D-2
Securing the cable ...........................................2-18
Typical response curve E-1, E-2
Verifying the mounting location................2-10
Tensile strength D-3
Transducer separation.........................................2-11
Terminal housing
Transducer system
Ordering information B-2
Block diagram .......................................................1-3
Terminating the cable at the
machine case 2-19 Components of .....................................................1-1
Test and Calibration Kit 3-1 Features ...................................................................1-2
Tests Inappropriate applications .............................2-2
Transducer response curve 2-14 Material used in system components ......D-3
Verification test 3-2 Recalibration to other surfaces...................D-2
Theory of operation 1-3 Receiving and inspecting................................ A-1
Threaded body mount Storing the system..............................................3-1
Mounting the transducer 2-13 Theory of operation............................................1-3
Ordering information ........................................A-2 Troubleshooting the system ..........................3-4
Securing the transducer................................2-17 Verification test ....................................................3-2
Tip (see Probe tip) Verifying the performance...........................2-14
Torque, maximum case torque..........................D-3 Transducer wiring
Transducer cable Cable construction..............................................1-2
Cable construction............................................. 1-2 Connecting the transducer wiring ...........2-18
Mechanical drawings........................................C-1 Result of incorrect field wiring .....................D-1

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Differential Expansion Transducer System Operation Manual
Troubleshooting
Common installation errors.........................2-20
Cross coupling ...................................................2-11
Plated surfaces.....................................................2-8
Procedures 3-4
Using a response curve 2-14
Verification test 3-2

V
Verification Test..........................................................3-2
Vibration measurements, inappropriate
application....................................................2-2
Voltage
Power supply voltage range .........................D-1
Sensitivity to supply voltage...........................E-5
Troubleshooting incorrect power
supply voltage ............................................3-5

W
Warranty........................................................................3-1
Water-resistant housing ....................................... B-1
Weight, specification...............................................D-3
Wiring D-2
Cable construction..............................................1-2
Connecting transducer wiring ...................2-18
Mechanical drawings ....................................... C-1
Part numbers........................................................ B-4
Result of incorrect field wiring .....................D-1
Terminating the cable at the
machine case......................................2-1

60