MMC INTERNATIONAL CORP

OPERATING AND MAINTENANCE

INSTRUCTIONS

INTRINSICALLY SAFE TRIPLE FUNCTION GAUGING TAPE

FOR

CLOSED (GAS-TIGHT) APPLICATIONS

LIQUID MEASURE OF ULLAGE, OIL/WATER INTERFACE

AND TEMPERATURE

MODEL D-2401-2

TECHNICAL APPROVED BY:

CSA/ATEX FOR CLASS I, DIVISION I, GROUPS C & D
AND
LLOYD’S REGISTER, BUREAU VERITAS “MED” APPROVED

IN ACCORDANCE WITH IMO RESOLUTION MEPC.5 (XIII)

FOR OIL/WATER DETECTION

MMC INTERNATIONAL CORP.

60 INIP DRIVE
INWOOD, NEW YORK 11096

SEPTEMBER 2022 DRAWING FILE NO. A-2401-60AC REV A

 TABLE OF CONTENTS
PAGE NUMBER
NOTICES i

User instructions (in compliance with 2014/34/EU Directive, Annex II, 1.0.6) ii

MMC Atex/IECEx definition iii

I. GENERAL 1

1.0 SPECIFICATIONS 1

1.1 LINEAR ACCURACY SPECIFICATIONS 2

1.2 SPECIAL FEATURES 3

II. INTRODUCTION 4

III. THEORY OF OPERATION 5, 6

IV. REQUIRED CONDITIONS AND RECOMMENDATIONS FOR

SAFE USAGE 7

4.1 REQUIRED CONDITIONS 7

4.2 RECOMMENDED SAFE USAGE CONDITIONS 7

4.3 GROUNDING PRECAUTIONS 7, 8

V. GAUGING TAPE OPERATION 9

5.1 TANK ENTRY 9

5.2 PRODUCT GAUGING OPERATION 9

5.3 DETERMINING CARGO LIQUID LEVEL 9

5.4 USE OF THE SECONDARY TAPE SIGHT PORT 9, 10

5.5 TAPE OVER-WIND AND OTHER CONDITIONS 10

5.6 SIGHT PORT GLASS CLEANING 10

VI. OPERATION 11

6.1 FAMILIARIZATION WITH OPERATING CONTROLS

& FEATURES LOCATED ON THE TAPE REEL HUB COVER PANEL 11

CONTINUED ON NEXT PAGE

CONTINUED

6.2 ULLAGE/INTERFACE MEASUREMENTS 11, 12

6.3 TEMPERATURE MEASUREMENT PROCEDURE 13

VII. CARE AND MAINTENANCE 13, 14

VIII. CALIBRATION PROCEDURE 15

8.1 ULLAGE AND INTERFACE 15

8.2 TEMPERATURE SENSOR CALIBRATION 15, 16

IX. GAUGING TAPE REPLACEMENT 17, 18

X. HUB COVER AND P. C. BOARD REPLACEMENT 19

XI. FAULT FINDING 20, 21

XII. APPENDIX 22

XIII. WARRANTY 23

IVX. GLOSSARY OF APPROVALS 24

VX. TEMPERATURE CONVERSION CHART 25

XVI. LIST OF CHEMICALS 26

XVII. GUIDELINES FOR TAPE REPAIR 27

XVIII. LIST OF DRAWINGS 28

 NOTICE TO ALL EQUIPMENT USERS

The triple functions of this sensor are to detect cargo surface level, Ullage, the Interface between two
immiscible products such as oil and water, and cargo Temperature.

The normal order of the gauging device, response to the products “Ullage level”, is a steady horn tone.
The normal response to an “Interface level”, (i.e., between a non-conducting and an electrically
conducting product such as a petroleum product and water, is a “steady” tone changing to a “beeping”
tone at the interface level.

A special note to our chemical customers, is the fact that some chemical cargoes may be
inherently conductive.

Therefore, at the surface of a conductive product’s Ullage level, a “beeping” tone will be the normal
response.

As a further note to the above, the change in detection of a non-conductive product Ullage level as a
steady tone to that of a conductive product’s ullage “beeping” tone, it is not to conclude that the sensor
is malfunctioning.

Best Regards,

MMC International Corp.

i
User instructions (in compliance with ATEX 94/9/EC Directive, Annex II, 1.0.6)

The following instructions apply to the Flexidip Portable Gauging Tape Type D-2401-2** covered by
certificate number BAS 02ATEX1274X. The information contained herein shall be included with every
batch of products sold, either as a separate sheet or incorporated as a discrete section in an instruction
manual.

WARNING: USE ONLY DURACELL/PROCELL MN1604 BATTERY REPLACEMENT.

DO NOT REPLACE BATTERY WHERE AN EXPLOSIVE GAS ATMOSPHERE MAY BE PRESENT.

BE AWARE OF POTENTIAL ELECTROSTATIC CHARGING HAZARD AFTER LOADING

DISTILLED PETROLEUM.

THIS DEVICE MUST BE GROUNDED.

Instructions for safe selection, installation, use, maintenance, and repair

1 The equipment may be used in zones 0, 1, or 2 with flammable gases.

2 The equipment may be used in the presence of flammable gases and vapors with apparatus
groups IIC or IIB or IIA and with temperature classes T1 or T2 or T3 or T4.

3 The equipment is certified for use in ambient temperatures in the range of –20°C to +40°C and
should not be used outside this range.

4 The equipment is to be installed by suitably trained personnel in accordance with the applicable
code of practice (typically IEC EN 60079-14).

5 The equipment does not require assembly or dismantling.

6 With regard to safety it is not necessary to check for correct operation.

7 No user adjustment is required.

8 Regular periodic inspection of the equipment should be performed by suitably trained personnel
in accordance with the applicable code of practice to ensure it is maintained in a satisfactory
condition.

9 The equipment is not intended to be repaired by the user. Repair of the equipment is to be
carried out by the manufacturer, or their approved agents, in accordance with the applicable
code of practice.

10 The equipment contains no other customer-replaceable parts.

11 The apparatus shall not be subjected to a prolific charge generating mechanism (such as might
occur in pneumatic transfer of powders or charge spraying in a powder coating process).

12 If the equipment is likely to come into contact with aggressive substances, e.g., acidic liquids or
gases that may attack metals or solvents that may affect polymeric materials, then it is the
responsibility of the user to take suitable precautions that prevent it from being adversely
affected thus ensuring that the type of protection is not compromised.

ii
 SECTION I
1. GENERAL

1.0 SPECIFICATIONS:

Display Readable Temperature Range °F = -40° to 199.9°*

*Reading Limit Due to 3-1/3 Digit LCD Display on °F Range °C = -40° to 150.0°

Guaranteed Temperature Calibration Range 32°F to 190°F

(0°C to 88°C)

Accuracy Over Calibration Range ±0.5°F (±0.2°C)

Accuracy Linear Measurements ±1/8” (±2.0 MM), Plus ±0.1%

of Total Tape Length, worst case

Minimum Detectable Tank Bottom Liquid Level 3/8” (10MM)

Minimum Detectable Floating Product Level 1/8” (3MM)

Batteries for Intrinsically Safe Operation Only Duracell MN1604

(supplied)

Battery Drain (Temperature Mode) 1.3 ma (In Air)

2.6 ma (In Fluid)

Display 3-1/2 Digit Liquid Crystal

Display 1/2” Character Height

Operating Temperature Limit of Liquid Crystal Display, -40°F to 176°F

-40°C to 80°

Storage Temperature Limits -67°F to 185°F

-55°C to 85°C

Available Tape Length, *Single Face Scales 50 FT (15 Meters)

65 FT (20 Meters)
75 FT (25 Meters)
100 FT (30 Meters)
*100 FT (10ths & 100ths)
35M, 40M

Hazardous Environments Certified Intrinsically Safe

BASEEFA/SIRA,
Gas Groups C & D

1
1.1 LINEAR ACCURACY SPECIFICATIONS:

MMC PORTABLE ELECTRONIC GAUGING TAPE

STANDARD PRODUCTION
LINEAR MEASUREMENT ACCURACY

Applicable Equipment: MMC Models D-2401-2 (Trimode),

D-2401-2UI (Ullage/Interface)

Tape Lengths: 50FT., 65FT., 75FT., 100FT. and

15M, 20M, 25M, 30M, 35M, 40M.

Basic Gauging Tape Style: Steel, 0.375 wide x 0.006 thick,

yellow or white faced, black & red
graduation markings. Manufactured in
accordance with API Chapter MPMS 3.1A
industrial guideline.

System Linear Accuracy: English Reading, ±1/8" of reading

Metric Reading, ±2MM of reading

plus +/- 0.01% of total tape length.

GENERAL STATEMENT OF LINEAR ACCURACY

MMC warrants that the above listed, newly produced equipment models, incorporating the listed basic
gauging tape style and lengths, will perform to the stated system accuracy.

Certification of accuracy for new equipment is available at an extra cost. Certification costs to standards
of accuracy more precise than the stated system accuracy will be quoted upon request.

2
1.2 SPECIAL FEATURES:

Conductive Tape Surface to Drain Off any Static Charge

Grounding Cable with Heavy Alligator Clamp

Dual-Purpose Spring-Loaded Tape Crank and Tape Position Lock

Watertight Electronics Construction with Sealed Switches

All Stainless-Steel Fasteners

Nylon Coated Aluminum Reel Housing for Lightweight Portability

Low Battery Display Indicator

High Daylight Visibility with Liquid Crystal Display

Push-Button Night Light

Rapid Multiple Temperature Measurements

Easily Renewable Tape Wiper

Manually Operated Vacuum/Pressure Relief Valve

Primary and Secondary Tape Sight Glasses

Anti-Wind Internal Spring-Loaded Stop Lever Sensor

Internal Tape/Reel Confinement Springs

Gas Tight Construction

3
 SECTION II

2.0 INTRODUCTION:

2.1 The MMC Tri-Mode portable ullage, temperature and interface tape described herein
incorporates extremely accurate instrumentation to provide three vital petroleum and
other liquid tank measurements.

• Measurement of surface ullage level of oil or other fluids to an accuracy and

repeatability of ± 1/8 inch.

• Determination of the exact location of the ullage level of the interface layer
exists when an oil-water mixture is contained within the same vessel.

• Measurement in either Degrees F or Degrees C of the temperature of the fluid

within a vessel, at any or several desired ullage levels, in rapid succession.
Measurement is given to the nearest 0.1 degree and is accurate to ±0.5°F over
the calibrated temperature ranges given in the specifications listed in
Section I.

2.2 The MMC system utilizes a sensor suspended at the end of a fluoropolymer covered
gauging tape wound on a reel assembly. The plastic covered steel gauging tape
contains two isolated side conductors to carry the signal and power to the electronic
circuit within the sensor barrel with the steel tape, provides the ground return. The plastic
surface of the tape has been treated to make it sufficiently conductive to prevent the
build-up of static charges. Temperature indication is provided by a large digital liquid
crystal display (LCD), housed within a sealed reel driving assembly.

2.3 Ullage and interface detection is provided by an audible signal obtained from a horn
in the reel driving hub, when the bottom “U” gap in the sonic sensor is immersed in fluid.
The audible signal heard will be a continuous tone in a non-conductive fluid such as oil,
gasoline, kerosene, etc., but will change to an interrupted tone when immersed in a fluid
which is electrically conductive, such as water.

2.4 The system is certified as intrinsically safe for electrical equipment in hazardous
atmospheres by SIRA, CSA, BV, DNV.

2.5 The triple function temperature, interface, and ullage sensor is powered by a single 9-volt
battery contained within the hub assembly. Battery drain is extremely low,
(approximately 1-1/4 Milliamperes in either the ullage, interface, or the temperature
mode), ensuring very long operation, without battery replacement. Low battery warning
is provided at the upper left corner of the temperature display LCD, when the battery
voltage has dropped to a level that would, with further operation, cause excessive errors
in temperature readings.

4
 SECTION III
3.0 THEORY OF OPERATION:

3.1 Drawing S-2562-1TR illustrates the main components of the closed Temperature, Ullage,
and Interface system. A tape reel contains the calibrated tape. The reel crank on the
driving hub is used by the operator to raise and lower the sensing head assembly which is
attached to the reel via the tape. Before lowering or raising the tape, the reel brass thumb
screw lock must be unlocked.

3.2 The sensor head assembly contains two piezo-electric crystals, a pair of interface or
conductivity pins and a temperature sensor, located in one of the conductivity pins and
electronic circuit board. The sensor is connected electrically to the driving hub
electronics by the two wires encased in the gauging tape plastic jacket, which covers and
hermetically seals these wires and centers graduated metallic gauging tape. The metallic
tape is used as a ground return conductor, which when including the two wires straddling
it, form a rectangular three conductor transmission cable.

3.3 The electronic circuits in the hub assembly are comprised of an LCD digital display
which provides temperature readings when the system is in the temperature mode; an
analog to digital converter, a power on-off switch, a mode switch which permits operator
to select the temperature mode or ullage/interface mode, a night light switch and ancillary
electronic parts all assembled on a printed circuit board. A 9-volt battery power source
and audio horn are located within the tape reel hub assembly below the P.C. board of the
modular hub cover assembly.

3.4 When the system is placed in the ullage/interface mode, and as the sensor is immersed in
a non-conductive fluid such as oil, a sonic signal originated by the sensor head circuits
freely crosses the sensor gap and is detected, amplified and then transmission tape to the
hub electronics board, which in turn drives a horn in the turning drum assembly. A high
pitched continuous audible signal is then emitted. When the sonic sensor is in air, the
sonic signal does not cross the sensor gap and therefore the horn is silent.

3.5 When the sonic sensor is immersed in a conductive fluid, such as the water layer side of
an oil/water interface, operation is as above except that the conductivity pins within the
sensor gap now permit a minute current to flow between the pins. This current flow is
detected by the sensor electronic circuitry with the sensor housing and suitably
conditioned to cause the sonic signal to be periodically interrupted, yielding a “beeping”
tone for operator identification.

3.6 When the system is placed in the temperature mode the ullage and interface circuits
within the sensor barrel are de-energized, also disengaging the audio signals associated
with the ullage/interface mode. The integrated circuit temperature sensor housed within
the grounded interface pin now functions as an extremely accurate linear temperature to
current transducer. As the temperature at the sensor rises, so does the temperature sensor
current. By passing the temperature sensor current via the transmission tape, through the
electronic component network, with the turning drum, input to an A to D converter is

5
 caused to vary linearly with temperature. Span control (R18) is adjusted to provide a
fixed reference voltage, to scale for either, to scale for either a Centigrade or Fahrenheit
reading device. Coded digital output from the A to D converter to the LCD Display is
used to prove accurate and fast temperature readings.

The two potentiometer controls, R13 and R18, perform as a two-point temperature calibration
adjustment.

A complete temperature calibration procedure is later described in this manual. (See section
VIII).

Temperature recalibration is recommended at yearly intervals. Please note that units returned
for Temperature Calibration during standard or extended warranty periods are not covered by
warranty statement.

3.7 New Addition LED to existing PCB. When the electronic probe is lowered and senses a
hydrocarbon, a steady horn tone is sounded and LED illuminates. When sensing an oil-water
interface, or a heavier than water non-conductive liquid, and intermittent horn tone sounds, and
LED begins flashing.

6
 SECTION IV
4.0 REQUIRED CONDITIONS AND RECOMMENDATIONS FOR SAFE USAGE:

The attention of the user of this apparatus is drawn to the possible hazards of ullage, interface,
and temperature measurements within flammable liquids, which are known to be generators of
static electricity.
Adhering to the specific safety directives of your company is the responsibility of the user.
The following is a general guideline to safe usage, drawn from the advice and experience of
various industry sources.
The specific safety standards or directives of your company are to be strictly adhered to, with the
general guidance given here being regarded as only a supplement to existing and established
operating safety procedures.

4.1 REQUIRED CONDITIONS:

This apparatus must be earthed (grounded) to the liquid tank containment vessel or tank,
before and during introduction into the vessel. The earthed conductor must not be
disconnected until the apparatus is completely withdrawn from the vessel being gauged.
A suitable grounding cable is provided as part of the gauging unit. Proper grounding of
this cable is the responsibility of the user.

4.2 RECOMMENDED SAFE USAGE CONDITIONS FOR THE TRIPLE FUNCTION

GAUGING TAPE:
As the word “Closed” implies, the Tri-Mode gauging assembly shown on drawing S-
256201TR has been carefully constructed to eliminate the escape of cargo vapors to the
atmosphere and to minimize exposure of operating personnel to these vapors. The sealed
construction utilized meets the current state and federal environmental requirements and
provides the operator with a tool which greatly reduces potential occupational hazards.

To assure that the above conditions will prevail, the “Closed” Tri-Mode gauging system
should be entered into a cargo tank by means of a deck station vapor valve.

4.3 GROUNDING PRECAUTIONS:

The “Closed” gauging tape assembly is to be hull grounded before and during its use for
cargo gauging. Grounding of the gauging unit with the provided coiled grounding
cable should be completed before the vapor valve is opened and any measurements
conducted. The unit must remain grounded during all measurement procedures and until
the sensor is fully wound back up into the case and the valve is closed.

4.3.1 The grounding of the unit and adhering to the specific company safety standards
or directives, is the sole responsibility of the operator.

4.3.2 Sensor entry into tanks or vessel immediately following a tank filling or loading
operation of known static accumulator type petroleum products or other such
flammable liquids, should not be attempted until, at least a period of 30 minutes
has elapsed since the cessation of filling.

7
4.3.3 Clean oil distillates are, in general, known to be accumulators of static electricity
due to their low conductivity (i.e., less than 100 Pica Siemens/Meter) and
therefore may require relaxation periods of longer than 30 minutes before gauging
is attempted.

4.3.4 The foregoing does not consider the use of anti-static additives to clean oils, as
generally easing the need for proper precaution, unless actual and specific product
testing has shown the product to have conductivity levels which eliminate the
danger of static electric charging.

4.3.5 Sensor entry into tanks or vessels that have been water washed and which
previously contained, or still partially contain petroleum products is not
recommended unless a sounding pipe is provided, and approved for such use, or
at least a period of five hours has elapsed since completion of the working
operation.

8
 SECTION V
5.0 GAUGING TAPE OPERATION:

5.1 TANK ENTRY:

5.1.1. The closed tape is installed into a vapor control valve in the same was as a
restricted Flexi-Dip model. However, since the closed unit is sealed, an air
cushion may occur, preventing the “Closed” tape from easily seating into the
valve. BY depressing the vacuum/pressure relief valve located on the top of the
“closed” unit, the back pressure is release, allowing the unit to properly seat. The
securing collar on the storage tube barrel is then tightened on the valve.

5.1.2 In addition, the vacuum/pressure relief valve can be used to determine the
pressure within the case. Unscrewing the valve actuator cap exposes the actual
valve. This valve is similar to an ordinary bicycle tire valve and has its own
attached to the valve by means of the exposed threaded valve stem. After pressure
readings are complete, screw that valve actuator cap back onto the valve.

5.2 PRODUCT GAUGING OPERATION:

5.2.1 The tape sensor, lowered and raised by unwinding and rewinding the tape
crank/reel lock assembly, is located on the reel driving hub, which is spring-
loaded (perpendicular to the hub faceplate), the sensor can be freely lowered by
turning the reel hub clockwise

To lock the reel at a desired tank depth, pull the knurled knob up and out of its
hub socket and rotate it downward against the case. The reel is not locked. To
unlock the reel, reverse the above procedure.

5.3 DETERMINING CARGO LIQUID LEVEL:

Upon sonically determining the liquid level, (previously described), the gauging tape
scale is read through the primary gauging sight port, located on the bottom side of the
gauging assembly directly above the tape wiper housing. With a vapor valve properly
installed, the tape reading will be corrected to the “zero” ullage reference pane.

After completing a reading, re-wind the tape to its stowed position, being careful to
engage the spring-loaded tape wiper.

5.4 USE OF THE SECONDARY TAPE SIGHT PORT:

5.4.1 A secondary tape sight port is provided for two main purposes. This port is
located at the top of the unit, just below the carrying handle. With the carrying
handle rotated to the case cover side, the secondary port may be viewed directly.

5.4.2 When lowering or raising the tape, the motion of the gauging tape should be
observed through the secondary port. Viewing the tape through the secondary port
gives the operator an immediate sense of tape direction, and approximate pay-out
location of the sensor. When using a closed unity, as opposed to a restricted or
open mode, a sense of tape direction may not be obvious to new operators.

9
 Therefore, the use of the secondary sight port becomes an important part of
normal operations.

5.4.3 When tape motion is stopped, the tape reading seen in the “secondary” sight port
is exactly 300MM above “zero” ullage reference level.

CAUTION:

If the gauging tape reading seen at the secondary sight port is to be used as a
recorded ullage, 300MM must be subtracted from reading to correct the
“zero” ullage reference plane.

5.4.4 In addition to the above functions, the secondary port provides an easy means of
determining oil-water interface layer measurements. Ince interface measurements
are only concerned with relative differences, the previously mentioned 300MM
corrective subtraction becomes unnecessary.

5.5 TAPE OVER-WIND AND OTHER CONSIDERATIONS:

The closed gauging tape is provided with an automatic anti-wind mechanism. The
purpose of this mechanism is to prevent the operator from re-winding the tape, after
having fully payed-out the tape length, in an opposite fold over sense. When a tape is
fully extended, a hard stop to further tape reel rotation will occur. Do not force this stop,
as tape damage may result. When a tape travel stop is encountered, please observe the
tape re-wind level for the proper re-wind direction.

Internally, spring band fingers have been positioned around the tape take-up reel, to
prevent the tape from coming out of the reel. However, in the event that the assembly is
inadvertently dropped a good distance with a tape not fully rewound, the gauging case
cover should be removed for an internal inspection.

5.6 SIGHT PORT GLASS CLEANING:

Occasionally, sight glass cleaning may become necessary. With reference to drawings A-
2562-146 and A-2562-147, cleaning may be easily accomplished. Cleaning may be most
easily accomplished by unscrewing the entire assembly and washing in a suitable
detergent.

CAUTION!
To maintain the sealed integrity of the gauging assembly, be sure that the case seal “O”
ring, Part No. 5 is in place upon re-installation of sight ports.

10
 SECTION VI

6.0 OPERATION (Refer to Figure 1):

6.1 FAMILIARIZATION WITH OPERATING CONTROLS AND FEATURES ON

THE TAPE REEL HUB COVER PANEL:

6.1.1 Turn on power by momentarily depressing the “On/Off” push-button switch (1)
located at left of panel. The display should read 1XX.X* indicating that the
system is in the Ullage/Interface mode.

6.1.2 Looking at the top left-hand corner of the LCD display, notice if the symbol “LO
BAT” appears. If the symbol is displayed, the battery voltage is low, and the
battery should be replaced (see Section VII Paragraph 7.5). Always replace the
battery if “LO BAT” appears even though the digital display turns on.
Temperature readings with a low voltage batter (below 7.0 Volts) are unreliable.

6.1.3 Once again, momentarily depress the power “On/Off” switch. Note that the
display turns off. Always turn power off when the system is not in use to prolong
battery life.

Depress the “On/Off” switch once more. Display turns on and reads 1XX.X*
indicating the Ullage/Interface mode.

*NOTE: Due to an inherent digital uncertainty of the A to D converter, some

digital displays, whenever is the Ullage/Interface mode, will read 00.0
instead of 1XX.X.

6.1.4 Now momentarily depress the “Mode” switch at the right of the panel. The
display should now switch to the temperature mode as indicated by a reading on
the display indicative of the temperature of the sensor tip.

Once again depress the “Mode” switch and not that the display reads 1XX.X*
(Ullage/Interface Mode). Depressing the “Mode” switch alternately changes the
function from temperature to Ullage/Interface and vice versa. Depressing the
power “On/Off” switch alternately turns power off or on regardless of which
mode was in operation. However, when power is switched on again the system
will always come on in the Ullage/Interface mode.

6.1.5 Depress the night light switch (3) at upper center of panel when it is too dark to
see the display. The display background will illuminate, and the reading should
now be discernible.

6.2 ULLAGE/INTERFACE MEASUREMENTS:

6.2.1 If power is off, depress power “On/Off” push-button switch. The system comes
on in Ullage/Interface mode (display reads 1XX.X).

6.2.2 If the power was on and the system is in temperature mode, depress the “Mode”
switch at right of panel to alter function to Ullage/Interface.

11
6.2.3 Make sure “LO BAT” does not show at left upper corner of display.

6.2.4 After grounding the assembly, insert the barrel of the gauging unit into the valve.
Un-lock the tape reel lock by rotating the brass lock thumbscrew
counterclockwise turning position hub seat. Grasp the knurled reel crank hand and
lower the sensor head tape assembly, which contains the sonic sensor, into the
tank. Always exert a retraining force to prevent the sensor from descending too
rapidly or free falling.

CAUTION!

Under no circumstances should the reel and tape be permitted to unwind without
restraint. Permanent damage may be incurred to the sensor head or to the
calibrated tape if the head is permitted to fall freely.

6.2.5 Lower the sensor head slowly until a steady tone is heard. If the surface of the
fluids is oil or other non-conductive fluid, a continuous audible tone will be heard.
If the surface of the fluid is water of other conductive fluid, the audible tone heard
will be a “beeping” tone.

6.2.6 Define measurement by raising the sensor head until the sound just ceases. Lower
until sound is just heard again, to refine ullage level.

6.2.7 Place gauging tape against ullage referenced point and read ullage on tape. Note
this reading as the surface liquid ullage level.

6.2.8 To find the oil-water interface point, continue to lower the sensor into fluid,
noting that the audible tone is continuous. When the audible signal changes to a
“beeping” tone, the sensor has entered the water column underneath the oil.

6.2.9 Raise the sensor very slowly until the tone once again becomes continuous.
Repeat if necessary to refine water entry point (Interface level).

6.2.10 Again, read the ullage on the tape. By subtracting the first reading obtained (step
7) from this reading, the total product depth is thus determined. By subtracting the
second water level ullage from the maximum tank depth, water level innage is
determined.

6.2.11 When the measurement is completed, place the spring-loaded wiper knob in the
“On” position while rewinding the tape until sensor is stored with the vapor valve
entry barrel. Do not close the vapor valve until the fully “stowed” position is
confirmed, by noting that yellow pop-up button on top of the wiper housing is up.

6.2.12 Lock the reel by rotating the crank/reel lock thumbscrew down position parallel to
hub. Depress power “On/Off” switch to conserve battery power.

6.2.13 Close the vapor valve, disconnect the valve securing cap, remove the gauging
unit, disconnect the grounding cable. Replace the vapor valve cap.

12
6.3 TEMPERATURE MEAUREMENT PROCEDURE:

6.3.1 If power is off, turn unit on by depressing “On/Off” push-button switch. Unit
comes on in Ullage/Interface mode. Depress “Mode” push-button switch to select
temperature.

6.3.2 If unit was on and in Ullage/Interface mode, simply press the “Mode” push-button
to select temperature.

6.3.3 Make sure “LO BAT” does not show at left upper corner of display. If “LO BAT”
appears, replace battery even though the digital display turns on. The display may
continue to operate even though the battery voltage is below normal. Temperature
reading however, may be in error.

6.3.4 Ground the assembly, release the turn handle reel lock. Lower the sensing sensor
to the deepest reading desired. Make sure to exert restraining force while
lowering.

6.3.5 When the desired temperature ullage level is reached, allow the sensor to rest at
this point for at least two (2) minutes. Then joggle the sensing sensor up and
down, approximately 6” above and below the desired measurement level until the
displayed temperature reading settles. Record this reading. For heavy crude oil
products, the joggling procedure is a necessity to ensure accurate readings. The
viscous nature and low thermal conductivity properties of these petroleum
products makes the joggling procedure a necessity to ensure accurate temperature
in a minimum amount of time.

6.3.6 Raise the sensor to the next ullage level to be measured. Repeat step 6.3.5.
Continue raising sensor to all levels at which readings are desired.

6.3.7 When the measurements are complete, push “On/Off” button to turn off and
conserve battery power. Rewind the tape into the carriage reel assembly. Wipe the
tape as it is rewound by placing the spring-loaded wiper in the “On” position.

6.3.8 Lock the reel by rotating reel lock crank down, position. Follow the same
procedure as described in step 6.2.13.

7.0 CARE AND MAINTENANCE:

Proper care and maintenance should be practiced to maintain long, trouble free and accurate
service and to maximize battery life, as follows:

7.1 When not in use, make sure power is off as evidenced by display being extinguished.

7.2 Store sensor head assembly in the fully wound position and store in a dry location. Do
not allow the instrument to remain for long periods in direct sunlight, or store in
temperature above 125° F, or in temperature below freezing. Such temperatures may
damage the liquid crystal display.

13
7.3 Wipe excess oil or water from tape, and sensor head. Each time the sensor is raised from
the tank, hold the spring-loaded tape wiper switch in the “On” position.

7.4 Never permit tape and sensor head to unwind freely (control speed of descent by usage of
a restraining force on crank).

7.5 BATTERY REPLACEMENT (See Approval Label for correct type):

The battery should be replaced whenever the “LO BAT” symbol appears at the upper left
corner of the display. If the sensor is used to obtain temperature reading when the battery
is low, large errors may result. Always replace battery in a gas free atmosphere. Remove
the six machine screws on the hub cover. Lift the cover with its attached P.C. Board. The
battery is retained within the reel turning drum by a spring clip battery holder. Remove
the battery from the battery cap connector. Replace the battery with a fresh battery of the
type listed on the approval label only. Take care to align the viton cover casket, and
machine screw fasteners when re-assembling to tape reel hub.

14
 SECTION VIII

8.0 CALIBRATION PROCEDURE:

8.1 ULLAGE:

The ullage circuits do not require calibration in the field with proper care and handling
the equipment should function indefinitely.

8.2 TEMPERATURE SENSOR CALIBRATION (Field Operation Only):

The temperature sensor and its associated electronic circuitry have been accurately
calibrated at the factory. Temperature calibration by MMC is recommended at twelve-
month intervals, with periodic checks being carried out as necessary between these
intervals.

Before attempting any calibration, make sure that the battery is at a proper voltage level
as evidenced by the fact that “LO BAT” does not appear at the upper left corner of the
display when the equipment is powered. Low battery voltage will produce errors in
temperature readings. If “LO BAT” appears on the display, check battery voltage and
replace. If necessary, calibration of the temperature sensor may be accomplished as
follows:

8.2.1 Use thermometers accurate to ±0.1° and preferably graduated in one-tenth degree
intervals. If mercury thermometers are employed, use two separate thermometers
to provide greater resolution. One to cover low temperatures and the other to
cover the high temperatures.

8.2.2 Remove six machine screws on the hub cover. Lift the cover and attached P.C.
Board from Hub exposing two potentiometers at back lower left of board. Lowest
potentiometer, marked (R13), is the “Zero” control and the potentiometer to the
left and above, marked (R18), is the “span control. (See drawing B-2401-31).

8.2.3 Turn display on by depressing power “On/Off” button momentarily. Place system
in temperature mode by depressing “Mode” switch. Display should now read
temperature at sensor tip.

8.2.4 Prepare two temperature baths, a cold bath of approximately one-gallon of water,
and a hot bath of approximately one gallon of water at a temperature of at least
60° higher than the cold bath.

8.2.5 Place the sensor in the cold bath with thermometer and stir the bath well to
equalize temperature. Keep sensor and thermometer together at approximately the
same point in the bath.

8.2.6 Record: Sensor Cold Reading as = pc (as read from digital display).

Record Reference: Thermometer Cold reading as = tc

15
8.2.7 Repeat the above procedure in a hot bath.

8.2.8 Record: Sensor Hot Reading as = ph (as read from digital display)

Record Reference: Thermometer Hot Reading as as = th

8.2.9 Calculate Zero Correction = tc (ph – pc) – pc

th – tc

8.2.10 Place sensor in cold bath. Stir and wait until sensor reading on display stabilizes.
Note reading and then adjust “Zero” control potentiometer marked (R13) so that
the zero-connection calculated in step 7.2.9 above is added to or subtracted from
the sensor reading. If the answer in step 7.2.9 is positive, add the correction, if
negative, subtract.

8.2.11 Now place thermometer in the cold bath with the sensor and stir. Now adjust the
“span” potentiometer until the two readings are equal (the displayed reading, and
the reading of reference thermometer).

8.2.12 Check readings in hot bath. Slight touch-up of “Span” control may be required.
Normally not more than a ±0.1 degrees correction is necessary if the calculated
measure “Cold” temperature procedure has been performed correctly.

The above method allows the operator to perform the calibration in one step. If
desired, and particularly if the error is minor, an adjustment of zero may be
performed in the cold bath to equal the thermometer reading. Then the span may
be adjusted in the hot bath. However, this procedure requires repetition until both
cold and hot bath readings are correct without further adjustment in either cold or
hot baths.

16
 SECTION IX

9.0 GAUGING TAPE REPLACEMENT (With or without new sensor attached):

The gauging tape used for the Trimode closed gauging system is similar but not interchangeable
with the gauging tapes used for restricted gauging systems.

The tapes used are bright white faced steel core type, which have been encapsulated with a
tefzel jacket. (Tefzel is a registered trade name of the DuPont Corporation). The taps are
terminated at the display electronics hub PCB module connection points, by soldered leads
within the tape reel internal core. The sensor is connected to the tape by means of a quick
connect plug to the tape socket plug.

As with all tefzel coated MMC gauging tapes, the outer surfaces are factory treated to render
the surfaces of the tapes with anti-static properties.

The patented process to achieve the desirable anti-static condition is not defeated by tape
wiping or cleaning with standard petroleum-based solvents.

Gauging tape replacement is not difficult, but requires careful attention to the travel path of the
tape as it exits from the tape reel assembly, passes over the interior guide rollers, cursor pin
assembly, anti-chafing rollers and on through the wiper housing.

9.1 To replace a tape, remove the vapor valve barrel, tape wiper assembly, stub barrel
connector and main reel housing cover.

9.2 With the main reel cover removed, the tape reel and tape pay-out through the wiper
housing can be seen. Take careful note of how the tape is directed around the various
roller and guides. In particular, note the tape path between the upper right-hand roller, the
guide roller just below it, cursor pin assembly, and tape wiper split ring bushing.

9.3 With the above in mind, or recorded with a simple hand sketch, the screws holding the
reel hub cover can be removed. The reel hub cover is both a reel interior cover, and also
the reel drive shaft to reel driver. The underside of the cover has a crossbar, which
couples it to the reel drive shaft assembly. The coupling action is accomplished by means
of the cover cross bar engaging the slotted ends of the drive shaft assembly.

With the reel hub cover removed, note that the outer reel plate is still retained to the reel
hub core by a single flat head screw.

Note that directly opposite the flat head screw (180° away) a small pinhead can be seen in
a reel plate hole on the same screw hole diameter as the flat head screw. Also, note that
the screw hole pin, is at this time, aligned with drive shaft coupling slots.

The interior electrical connector hub end of the gauging tape is not also in view. Note the
placement of the terminating epoxy molding piece at the end of the tape within the hub
core. Also, note the three wires leading to a connector and a separate black ground wire
emanating from the molding.

17
 Remove the black wire screw and unplug the connector by squeezing the mating
connector at the ribbed sides which are at opposite sides of the connector shell. Remove
the flat head screw holding the outer reel plate to the reel core. Note that the spring-
loaded anti-rotation arm cannot be seen pressing the outside layer of tape.

9.4 Next, unreel the tape and sensor head until the anti-rotation devices stop the tape from
unwinding further. The tape may now, with a little manipulation, be lifted out and pulled
out from the rollers and through the hole exiting from the barrel.

9.5 A new tape can now be installed in reverse manner. Be sure that the tape numerals face in
the same direction as the previous tape numerals faced. Thread the end of the new tape up
through the barrel, through the rollers and finally make sure to correctly place the end
with the molding and connector into the hub core, ensure that the anti-rotation arm is now
again pressing against the outside layer of the new tape. Now wind the tape on to the reel
by spinning the tape reel in a counterclockwise direction.

Next, plug the connector into its mate and reconnect the ground wire. Replace the outer
reel plate and it’s flat head screw attachment to the reel core.

With the partially assembled tape reel still freewheeling on the drive shaft, alight the
slotted end of the drive shaft, to be in-line with the flat head screw on the outer reel plate
and the reel core stop pin directly across from it. The reel hub cover can now be re-
installed by visually aligning its underside cross bar with the drive shaft end slots.
Replace all core cover screws.

9.6 The main reel housing cover can now be replaced. The screws provided for cover
attachment to the main reel housing, having built-in “O” ring head seals. Do not replace
these screws with ordinary machine screws.

Re-install the wiper housing, being sure to replace its mounting plate to the wiper gasket.

Re-install the stub barrel piece into the tape wiper housing. Be sure to first replace the
split full stop busing into the barrel adapter.

As a final check, the gauging tape may be hand unwound from the reel to its full length at
which time the anti-rotation arm engagement should be confirmed.

Rewind the freed tape with some slight hand drag.

9.7 If a new sensor has also been replaced with a new tape, perform a temperature calibration
in accordance with Section VIII. This is a mandatory procedure as the new temperature
sensor components must be calibrated to the electronic board within the reel turning
drum.

18
 SECTION X

10.0 HUB COVER AND P.C. BOARD REPLACEMENT:

To replace the turning drum hub cover and P.C. Board, follow the steps outlined below:

10.1 Remove the six machine screws from the hub cover, extract cover, gasket, and P.C.
Board.

10.2 Unplug battery cap.

10.3 Unsolder wires that go to small horn. (Note that these wires originate from the same strip
that connects the battery cap).

10.4 Now carefully examine three conductor strips that originate at the upper right-hand
corner of P.C. board. These wires may not be the same color code as the replacement’s
hub P.C. Board, and it is important that they be connected to the correct points. Note that
one wire (ground) has a terminal lug attached and therefore replaces the previous wire
with terminal lug.

10.5 Now make a note of the wires that go to top and bottom splices of outer tape conductors.
One of these wires goes to a point on the P.C. Board labeled “+V”. The other to a point
on P.C. Board labeled “SIG”. Note which goes to top and which goes to bottom
conductor. For example: “SIG” to top connector and “+V” to bottom connector.

10.6 Unsolder spliced conductors and remove the nut ground connecting the gauging tape to
the driving drum. This now completes disassembly, and the old hub assembly can be put
aside.

10.7 Position new hub cover and P.C. Board and solder to horn and insulate the two free wires
originating from the battery cap strip line. The polarity of these two wires is not
important.

10.8 Reconnect ground wire with terminal lug to driving drum ground post and replace and
tighten nut.

10.9 Re-solder and insulate “+V” and “SIG” wire to outer tape conductors taking careful
notice of where they originated. (See step 9.5 above)

10.10 Replace battery and connect battery cap.

10.11 Re-assemble hub cover and attached P.C. Board with six machine screws being careful to
line up neoprene gasket.

10.12 Perform temperature calibration in accordance with Section VII.

19
 SECTION XI

11.0 FAULT FINDING (See Drawing B-2401-31):

The following section covers only simple faults that may occur. No attempt has been made in
this section to cover highly technical faults.

PROBLEM NO. 1: Unit does not turn on when power “On/Off” switch is depressed.
PROCEDURE &
EXPLANATION: If unit does not turn on at all, check battery voltage using a voltmeter. If
battery voltage is lower than four (4) volts, because unit has been
accidentally stored for a lengthy period with power on, the voltage is too
low to illuminate display. Replace battery. (See Section VII Paragraph
7.5). If battery is okay, check power “On/Off” switch using an OHM
meter. Switch should normally show an open circuit. When depressed
OHM meter reading should be less than 2 Ohms. If switch is okay,
integrated circuit chip is probably at fault. Return to factory or service
center for repair.

PROBLEM NO. 2: Unit stays on all the time, even though “On/Off” push-button is depressed.
PROCEDURE &
EXPLANATION: This symptom is usually indicative of a faulty power “On/Off” push-
button switch. Check the switch with an Ohmmeter as explained in
Problem No. 1 above.

PROBLEM NO. 3: Unit turns on and off, however when “Mode” switch is depressed system
does not switch to temperature it stays in Ullage/Interface mode always.
PROCEDURE &
EXPLANATION: Use OHM meter to make sure “Mode” switch is normally open and when
depressed is closed. If switch is faulty, replace. If switch checks out okay,
problem is probably an integrated circuit chip. Return to factory for repair.

PROBLEM NO. 4: Temperature readings are erroneous.

PROCEDURE &
EXPLANATION: A) When display is on, does the “LO BAT” appear at the upper left
corner? If so, replace battery with a new battery following
procedure given in Section VII, Paragraph 7.5.
B) If “LO BAT” does not appear and display contrast in temperature
mode is not good and the decimal point is very faint or not visible,
check battery voltage using voltmeter. If voltage has fallen below
5.0 “LO BAT” may not appear. Usually, under these conditions the
temperature readings will show extreme errors.
C) If battery checks out okay, it is possible that the temperature sensor
in the sensing head may have been damaged by dropping unit or
unit may be out of calibration, due to sever exposure or abuse.

20
 D) Determine if sensor is still useful by following the calibration
procedure given sin Section VII.
E) If fault is not corrected, return to MMC for repair. Sensor or
integrated circuit chip may require replacement.

PROBLEM NO. 5: Liquid Crystal Display (LCD) does not function properly one or more
segments stay on or off all the time producing strange figures.
PROCEDURE &
EXPLANATION: Display contact may be corroded or dirty. Remove hub cover and
associated P.C. Board by first removing six machine screws. Remove the
three push-button switches and seal boot fasteners. P.C. Board and
associated display may now be separated from cover plate. Remove LCD
display bezel (see Dwg. B-2401-31) by first removing two machine
screws and nuts. Carefully lift bezel and liquid crystal display from blue
connector. Make sure that the long thin elastomer contact strips that fit
into the top and bottom horizonal slots of the connector are not lost.
Remove connector with associated contact strips exposing P.C. Boards
contacts. If corroded or dirty, wipe contact (bottom side only) with cotton
swab wet with alcohol, being careful not to saturate LCD with fluid.

CAUTION!
Do not spray contact cleaner on LCD display or permanent damage may
be incurred. Re-assemble in reverse order making sure elastomer contact
strips are inserted properly in blue connector horizontal slots. Note that
blue connector bottom pins fit into mating hose on P.C. Board for proper
alignment. If above procedure does not cure problem, then either display
or integrated circuit A/D converter is at fault. Spare display can be
substituted to isolate problem. Order from MMC together with new
connector.

PROBLEM NO. 6: Display is damaged, permanently discolored, broken.

PROCEDURE &
EXPLANATION: Order new display and connector from MMC and follow procedure given
in Problem No. 5 to replace.

PROBLEM NO. 7: Unit operated properly in temperature mode, however, when placed in
ullage mode, horn does not sound in water, or sound is extremely weak.

PROCEDURE &
EXPLANATION: Sonic sensor has probably been damaged by being dropped and
replacement may be required. Check unit in a container of clean lube oil,
and then in a container of water. If sensor does not respond per operating
procedure, then sensor replacement is probably necessary. Return to
factory.

21
 APPENDIX

PAGE
NUMBER

A. MMC Warranty Statemen t 23

B. Glossary of Approvals 24

C. Temperature Conversion Chart 25

D. List of Corrosive Chemicals 26

E. Guideline for Tape Repair 27

F. List of Drawings 28

22
 WARRANTY

MMC SONIC ULLAGE, INTERFACE, TEMPERATURE & TRIPLE FUNCTION TAPES:

The seller, MMC or its licensed agents, fully warrants equipment of its manufacture against defects in
materials or workmanship for a period of one year from the date of shipment. No other warranty period,
in excess of one year, may be expressed or implied by sub-agents or others, unless authorized in writing
by MMC. The liability of the seller under this warranty is limited, at seller’s option, solely to repair or
replace with equivalent equipment.

The seller, upon the expiration of the warranty period, has the option to apply a limited credit, not to
exceed the original equipment sales price, toward the purchase of a new piece of equipment, if returned
equipment is beyond reasonable repair. In any event, non-warranty repair charges will be quoted to the
buyer, for authorization, before repair work commences.

In the event of Returns for Warranty Repairs:

A. The buyer is to notify the seller in writing upon discovery of the defects.

B. Upon receipt of written authorization from the seller, the equipment is to be returned as directed,
transportation prepaid by the buyer.

C. Buyer is to disclose the use of this product within hazardous chemical substances. It is the
responsibility of the buyer to clean or decontaminate this product before returning for repairs.
Buyer’s refusal will void repair warranty at seller’s option.

D. If seller’s examination of such equipment disclosed tohis satisfaction that defects were not caused by
negligence, misuse, improper installation, accident or unauthorized repair or alteration by the buyer,
repairs will be immediately affected.

E. Buyer is to provide shipping instructions for the return, including mode of transportation. This
warranty does not include mechanical parts failure due to wear or corrosion from normal usage, nor
does it cover limited life electrical components or elastomer seals.

This warranty is in lieu of all other warranties, expressed or implied, including that implied of fitness
for a particular purpose to the original purchaser or to any other person. Seller shall not be liable for
consequential damages of any kind.

IMPORTANT:

The equipment has been certified as intrinsically safe instrument for only those classes or categories of
hazardous areas so stated on the equipment label, bearing the mark of the applicable approval agency.
No other usage is implied or otherwise authorized.

Unauthorized repair or component replacement by the user will void this warranty and may affect the
intrinsic safety of the equipment.

23
 GLOSSARY OF APPROVALS

MAJOR APPORVAL STANDARDS & GOVERNEMNT SPECIFICATIONS

ADOPTED BY MMC INTERNATIONAL CORP. FOR
CERTIFICATION, MANUFACTURE, INSPECTION CALIBRATION AND TESTING

INTRINSICALLY SAFE APPROVALS

CAS (CAN.) Sira Certification Service

CSA Canadian Standards Association
EECS Electrical Equipment Certification Service (U.K.)
CSA (EUROPE) CSA Group Testing IK Limited
BV Bureau of Veritas

GOVERNMENT REGULATORY BODIES APPROVALS

BV Bureau of Veritas
EECS Electrical Equipment Certification Service (U.K.)

INDUSTRY RECOGNIZED INSPECTION BODIES APPORVALS

ABS American Bureau of Shipping

CCS China Classification Society
DNV Det Norske Veritas (Norway)
LLOYD’S Lloyd’s of London (U.K.)
BV Bureau of Veritas

GAUGING TAPE AND OTHER MEASUREMENT SPECIFICATIONS

FEDERAL United States Government Specification

NIST National Institute of Standards & Technology Test
API American Petroleum Institute (Partial Adaptation)
ASTM American Society for Testing Materials

PERIODIC FACTORY INSPECTIONS BY REGULATING BODIES

CSA (UK) Performs annual inspections for SIRA/CSA for equipment approval provisions of
directive 2014/34/EU
CSA (CANADA) CSA performs quarterly inspections
BV Performs annual inspections
DNV Performs annual inspections
CCS Performs annual inspections

24
 TEMPERATURE CONVERSATION CHART

°C = 5/9 (°F-32) °F = (9/5°C)+32 Table Example:

Kelvin = °C +273.15 Rankine = °F +459.67 To Convert 1000°C to °F look up 1000 read left
To Convert 1000°F to °C look up 1000 read right

To °F From to °C to °F From to °C to °F From to °C

-0.4 -18 -27.78 165.2 74 23.33 323.6 162 72.22
+3.2 -16 -26.67 168.8 76 24.44 327.2 164 73.33
+6.8 -15 25.56 172.4 78 25.56 330.8 166 74.44
+10.4 -12 -23.33 176.0 80 26.67 334.4 168 75.56
+17.6 -8 -22.22 179.6 82 27.78 338.0 170 76.67
+21.2 -6 -21.11 183.2 84 28.89 341.6 172 77.78
+24.8 -4 -20.00 186.8 86 30.00 345.2 174 78.89
+32.0 +0 -17.78 190.4 88 31.11 348.8 176 80.00
+35.6 +2 -16.67 194.0 90 32.22 352.4 178 81.11
+39.2 +4 -15.56 197.6 92 33.33 356.0 180 82.22
+42.8 +6 -14.44 201.2 94 34.44 359.6 182 83.33
+46.4 +8 -13.33 204.8 96 35.56 363.2 184 84.44
+50.0 +10 -12.22 208.4 98 36.67 366.8 186 85.56
+53.6 +12 -11.11 212.0 100 37.78 370.4 188 86.67
+57.2 +14 -10.00 215.6 102 38.89 374.0 190 87.78
+60.8 +16 -8.89 219.2 104 40.00 377.6 192 88.89
+64.4 +18 -7.78 222.8 106 41.11 381.2 194 90.00
+68.0 +20 -6.67 226.4 108 42.22 384.8 196 91.11
+71.6 +22 -5.56 230.0 110 43.33 388.4 198 92.22
+75.2 +24 -4.44 233.6 112 44.44 392.0 200 93.33
+78.8 +26 -3.33 237.2 114 45.56 395.6 202 94.44
+82.4 +28 -2.22 240.8 116 46.67 399.2 204 95.56
+86.0 +30 -1.11 244.4 118 47.78 402.8 206 96.67
+89.6 +32 0.00 248.0 120 48.89 406.4 208 97.78
+93.2 +24 +1.11 251.6 122 50.00 410.0 210 98.89
+96.8 +36 +2.22 255.2 124 51.11 413.6 212 100.00
+100.4 +38 +3.33 258.8 126 52.22 435.2 214 101.11
+104.0 +40 +4.44 262.4 128 53.33 438.8 216 102.22
107.6 42 5.56 266.0 130 54.44 442.4 218 103.33
111.2 44 6.67 269.6 132 55.56 446.0 220 104.44
114.2 46 7.78 273.2 134 56.67 449.6 222 105.56
118.4 48 8.89 276.8 136 57.78 453.2 224 106.67
122.0 50 10.00 280.4 138 58.89 456.8 226 107.78
125.6 52 11.11 284.0 140 60.00 460.4 228 108.89
129.2 54 12.22 287.6 142 61.11 464.0 230 110.00
132.8 56 13.33 291.2 144 62.22 467.6 232 111.11
136.4 58 14.44 294.8 146 63.33 471.2 234 112.22
140.0 60 15.56 298.4 148 64.44 474.8 236 113.33
143.6 62 16.67 302.0 150 65.56 478.4 238 114.44
147.2 64 17.78 305.6 152 66.67 482.0 240 115.56
150.8 66 18.89 309.2 154 67.78 485.6 242 116.67
154.4 68 20.00 312.8 156 68.89 492.8 244 117.78
158.0 70 21.11 316.4 158 70.00 496.4 246 118.89
161.6 72 22.22 320.0 160 71.11 500.0 248 120.00

25
 LIST OF CHEMICALS

The following list of chemicals, although not all-inclusive, are known to attack PES, the material from which a
portion of the sonic liquid level sensor is made.

Prolonged submergence of the sensor should be avoided.

After submergence in any of these chemicals, a thorough cleaning of the sensor head should be conducted to
prolong sensor life.

*ACETALDEHYDE – CH3CHO *ETHYL ACETATE – CH3COOC2H5

*ACETONE – CH3CHOH3 *ETHYLENE GLYCOL – HOC3H4OH

*ANILINE – C6H5CL *METHYL ETHYL KETONE – C2H5COCH3

BENZALDEHYDE – C6H5CL *METHYLENE CHLORIDE – CH2CL2

CHLOROBENZENE – C6H5CL NITRO BENZENE – C6H5NO2

CRESOL – CH3C6H4OH *PHENOL – C6H5OH

*CYCLOHEXANONE – C6H10O *PYRDINE – C5H5OH

DICHLOROBENZENE – C6H4CL2 TOLUENE – C6H5CH2

1,2 DICHLORETHANE – CH2CLCH2CL TRICLOROETHYLENE – CLCH:CCL2

*These chemicals are known to be water soluble, ranging from very to slightly; while this information is
useful in sensor cleaning procedure, it will also make interface readings less accurate. In such case, good
interface readings will depend upon the relative specific gravities involved. In the extreme case of
dissolved water within a cargo, and upon ullage gauging of these chemicals, a beeping tone will be
heard instead of the normal steady horn tone. This sensor response should not be interpreted as a
malfunctioning unit.

26
GUIDELINES FOR TAPE REPAIR:

The MMC sonic Trimode tape is verified as Intrinsically Safe by SIRA and BASEEFA (British
Approvals Service for Electrical Equipment in flammable atmospheres) in the United Kingdom.

In order to maintain the validity of the approval, tape units can be repaired only by MMC or our
authorized guaranteed repair offices approved by SIRA, BV, DNV, BASEEFA, CSA. We cannot offer
that approval; it must be given by the approval agency.

To maintain our agreement with the above-mentioned approval agencies and yet accommodate our
customers as much as possible, we have developed three sets of modules, which can be purchased as
units and installed by the owners of the tapes. However, we must know the serial number of the tapes
involved in order to maintain our records properly.

The Modules Developed are:

COMPLETE HUB ASSEMBLY, consisting of P.C. Board with ancillary components, (without
battery) faceplate, nameplate, gasket, and battery connection cap (approval agency and temperature
scale °C or °F to be specified when ordering.

TAPE AND SENSOR ASSEMBLY, consisting of triple sensor, P.C. Board, screw and tape and header
assembly. (Tape length and type graduation to be specified by customer when ordering.

TAPE WIPER ASSEMBLY, consisting of wiper blades, ON/OFF knob, mounting plate and screws.

27
 LIST OF DRAWINGS

“CLOSED TAPE”

DRAWING
NUMBER REV. DESCRIPTION

A-2562-146 B Primary Sight Glass Assembly, Closed Hand Gauging

A-2562-147 A Secondary Sight Glass Assembly, Closed Hand Gauging

B-2401-31 A P.C. Board Component Placement & LCD Assembly

B-2401-72 C Sub-Assembly, Hub Cover plate and P.C. Board, ATEX

B-2562-92 B Tape Wiper to Barrel Assembly

B-2562-269 B Tape Wiper and Plate Sub-Assembly, Closed Hand Gauging

D-2562-117 E Sub-Assembly Case Closed Hand Gauging

S-2562-1MB A Outline Assembly Closed Triple Function Gauging Tape

(Ullage, Interface, Temperature)

28
 NITE LIGHT
X

TRI MODE

ULLAGE/ INTERFACE
TEMPERATURE LED

HORN TONE
STEADY
0 °C +88 HORN BEEPS
AT OIL- WATER
IN OIL INTERFACE

POWER MODE SELECT

OFF / ON U/I T°

X INTRINSICALLY SAFE APPARATUS X

BASEEFA 2813
Ex ia IIC T4 Ga
II 1 G
-20 °C ≤Ta ≤ +40 °C
BAS02ATEX1274X
PUSH PUSH

WARNING USE ONLY DURACELL/PROCELL MN1604 BATTERY REPLACEMENT

DO NOT REPLACE BATTERY WHERE AN EXPLOSIVE GAS ATMOSPHERE MAY
BE PRESENT.
SER. NO..
BE AWARE OF POTENTIAL ELECTRO-STACTIC CHARGING HAZARDS AFTER
LOADING DISTILLED PETROLEUM PRODUCTS . SEE INSTRUCTION MANUAL
THIS DEVICE MUST BE GROUNDED. SEE INSTRUCTION LABEL.
MMC INTERNATIONAL CORP.
INWOOD, NY MOD. D-2401-2

YEAR MANUF.

GOLD FILED BOXES