MMC D-2401-2 Manual

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