Measurement Computing MEAS LT User manual

MEAS LT
Level & Pressure
Transducers
USER MANUAL
1st EDITION, March 2013

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 1 of 31 1-800-745-8008
W[email protected]
Table of Contents
1.0 PRODUCT DESCRIPTION ....................................................................................... 3
General Characteristics ................................................................................................ 3
Care and Handling ....................................................................................................... 3
Calibration .................................................................................................................... 3
Approvals ..................................................................................................................... 3
2.0 PRODUCT ACCESSORIES & OPTIONS ................................................................. 4
Nose Caps & Pressure Connections ............................................................................ 4
810 SuperDry™ Vent Filter or 815 Aneroid Bellows .................................................... 4
Sacrificial Anodes ........................................................................................................ 4
Absolute/Sealed Gage Transducer .............................................................................. 5
Polyurethane & ETFE Jacketed Cable ......................................................................... 5
Lightning Protection ..................................................................................................... 6
Electrical Outputs ......................................................................................................... 7
Cable Hanger ............................................................................................................... 7
Submersible Cable Splicing Kit .................................................................................... 7
3.0 INSTALLATION & MAINTENANCE TIPS ................................................................ 8
General Installation Procedures ................................................................................... 8
Transducer Anchors ..................................................................................................... 8
Transducer Submersion ............................................................................................... 8
SuperDry™ Vent Filter (Desiccant) or Aneroid Bellow Installation ............................... 8
Cable Protection .......................................................................................................... 9
Bending of Cable ......................................................................................................... 9
Cable Compression...................................................................................................... 9
4-20 mA Wiring ............................................................................................................ 9
VDC Wiring ................................................................................................................ 10
Protective Cage Diaphragm Protector........................................................................ 10
Position Sensitivity ..................................................................................................... 10
General Maintenance Tips for Submersible Transducers .......................................... 10
Desiccant Maintenance .............................................................................................. 10
Clogged Nose Piece or Dirty Diaphragm ................................................................... 11
Cleaning your Transducer .......................................................................................... 11
Preparation ................................................................................................................ 11
Cleaning Steps ........................................................................................................... 12
Cleaning the Lightning Protection Data Line Protector .............................................. 12

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 2 of 31 1-800-745-8008
W[email protected]
4.0 WARRANTY & PRODUCT RETURN PROCEDURE ............................................. 13
Product Eligibility ........................................................................................................ 13
Merchandise Return Procedures ............................................................................... 13
APPENDIX A DRAWINGS & DIAGRAMS ................................................................... 15
APPENDIX B FREQUENTLY ASKED QUESTIONS.................................................... 17
APPENDIX C TRANSDUCER FIELD CHECKS & TROUBLESHOOTING .................. 20
APPENDIX D CALIBRATION CALCULATIONS ......................................................... 29

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 3 of 31 1-800-745-8008
W[email protected]
1.0 Product Description
General Characteristics
MEAS LT Level and Pressure Transducers use isolated diaphragm sensors that can be used in
aggressive applications with hostile fluids and gases. These sensors utilize a silicon pressure cell that
has been fitted into a stainless steel or titanium package with an integral, compliant stainless steel or
titanium barrier diaphragm. This sensor assembly is housed in a rugged 316 stainless steel or
titanium case which provides for a variety of level ranges from 2.3 ft (0.75 m) H2O through 692 ft
(210.9 m) H
2
O and pressure inputs from 1 psi (7 kPa) through 2000 psi (13 mPa). Our devices
feature internal signal conditioning. Standard outputs are 4-20 mA and VDC.
All units containing active electronic components have surge and reverse polarity protection. For
ease of use in the field, our transducers are permanently laser engraved with our logo and name,
wiring information, part number (P/N), serial number (S/N), date of manufacture (DOM), range,
excitation and output. L T transducers are offered in 1.0” (25 mm) diameters.
Care and Handling
Our transducers are designed for rugged use. However, they need protection from over pressure and
sharp impact. Penetrate the surface slowly, vertically and only to the depth necessary when lowering
a transducer into a liquid. Avoid dropping the unit from above the surface. Clean all transducers by
rinsing them in a mild detergent. Direct probing of the diaphragm or attempts to remove protective
screens will damage the sensor, voiding the warranty.
Calibration
Calibration reports unique for each transducer are available for all MEAS LT transducers. This option
must be ordered at time of order placement. Make sure you keep each calibration report. However,
should you misplace your calibration sheet; you can contact the factory and request a duplicate. All
MEAS LT Transducer calibrations are traceable to the National Institute of Standards and Technology
(NIST).
Approvals
UL and FM certification for intrinsic safety options are available for MEAS LT transducers. Their
respective installation control drawings can be downloaded from our website. Several of our product
lines also carry ABS approval. Most products are CE compliant to EN 61326-1:2006 and EN 61326-2-
3:2006. CE compliant units are labeled accordingly.
These units are designed for installation in a Class I, Division 1, Groups A, B, C, and D, Class II,
Division 1, Groups E, F and G, Class III, Division 1 hazardous location when connected to appropriate
apparatus such as those manufactured by R. G. Stahl, Inc., and others.

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 4 of 31 1-800-745-8008
W[email protected]
2.0 Product Accessories and Options
WARNING: POTENTIAL ELECTROSTATIC CHARGING HAZARD
In hazardous locations:
● Avoid building up static charge on case of data protector and plastic accessories.
● Use damp rag to wipe data protector and plastic accessories to avoid static build up.
Nose Caps and Pressure Connections
There are several different pressure connection options for the MEAS LT submersible level and
pressure transducer product line.
 The LTA features a ported nose cap (Delrin) with #8-32UNC-2B threaded-hole where weight
accessories can be attached.
 The LTB features a wide mouth non-fouling cage protecting a 2.75” PTFE flexible diaphragm.
 The LT1 features a ¼” – 18 female NPT pressure connection.
 The LT5 features a ¼” – 18 male NPT pressure connection.
 The LT7 features a ½” – 18 male NPT pressure connection.
WARNING: Caution must be exercised when inserting a screw into the nose cap as the
maximum insertion length should not exceed 0.175”.
810 SuperDry™ Vent Filter or 815 Aneroid Bellows
All submersible level transducers and pressure transducers with molded cable attachment require an
optional protective barrier that guards against moisture buildup in the cable vent tube. The 810
SuperDry™ vent filter and the 815 Aneroid Bellows are guaranteed to operate maintenance free for
one year. The 815 Aneroid Bellows can be used on submersibles with accuracies of ±0.25% FSO.
These barriers ensure reliable operation and long life as they protect sensitive electronic components
from mildew and prevent the formation of a liquid column in the vent tube. Any such liquid column
directly affects the instantaneous calibration of the transducer. Transducers with accuracy better than
+1 – 0.25% should only be protected with the 810 vent filter in order to maintain this accuracy.
Sacrificial Anodes
Our sacrificial anodes are made from a special zinc alloy formulated to guarantee continued
effectiveness over long periods. Because the anodes are 95% galvanic, they will not corrode unless
there is an electrolytic demand. The anode maintains a high driving potential throughout its 12 month
life, is self-sloughing and always exposes new zinc for the best possible protection. For those
applications where cable buoyancy is a problem, the sacrificial anode can be substituted for hanging
weights.
Sacrificial Anodes provide cathodic protection against galvanic corrosion for our submersible pressure

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 5 of 31 1-800-745-8008
W[email protected]
transducers. Galvanic corrosion occurs when dissimilar metals are placed in contact with an
electrolyte. This condition causes a potential difference to exist between the two metals, causing
electron flow between them. Corrosion of the less corrosion-resistant metal is increased and attack of
the more resistant metal is decreased. The 820 Sacrificial Anode is clamped to the exterior of a one-
inch bore submersible transducer. We also offer a 1" diameter pencil anode, the 825, that attaches to
the MEAS LTA nose cap.
Absolute/Sealed Gage Transducer
The sealed gage option for submersible transducers eliminates the need for a vent filter. The
standard output of a sealed gauge transducer is 4 mA at 14.70 psia. The output of the transducer will
need to be adjusted to compensate for the altitude difference with a separate barometric unit, if
necessary.
Polyurethane & ETFE Jacketed Cable
Most installations of our submersible level transducers connect our polyurethane or ETFE cable to a
junction box. From this junction box (P/N 840), users typically run their own cable to the required
instrumentation. Polyurethane-jacketed cable is used for most applications while ETFE material is
recommended for more aggressive environments.
Specifications for our standard polyurethane and ETFE jacketed cable are as follows:
Specifications
Standard
Submersible Cable
Standard
Non-Submersible Cable
Weight
0.05 lbs/ft (0.07 kg/m)
0.025 lbs/ft (0.035 kg/m)
Min. OD
0.28" (7.10 mm)
0.189" (4.8 mm)
Max OD
0.31" (7.87 mm)
0.19" (4.9 mm)
Conductors
4 - 22 AWG
22 AW G
Insulation
Conductors
Outer jacket
Polyurethane, ETFE or
PVC
Color coded PVC
Shield
36 gauge spiral tinned
copper wire foil shield with
drain wire
Aluminum/polyester foil
facing outward
Vent Tube
Polyethylene, .060" ID
(1.52 mm)
Drain wire
7/32 tinned copper

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 6 of 31 1-800-745-8008
W[email protected]
Chemical resistance of polyurethane:
Potable Water, Wastewater, Borax, Butane, Animal Fat, Carbonic Acid, Citric Acid, Cod Liver Oil,
Corn Oil, Glycerin, Glycol, Mineral Oils, Potassium Nitrate, Potassium Sulfate, Silicone Oils, Stoddard
Solvent, Tannic Acid (10), Tartaric Acid, Turbine Oil.
Chemical resistance of ETFE:
Acetic Acid (Glacial), Acetic Anhydride, Acetone, Aluminum Chloride, Anti- Freeze, Bromine, Calcium
Chloride, Calcium Hydroxide, Chlorine, Copper Chloride, Ferrous Chloride, Hydrochloric Acid,
Ketones, Lacquer Thinners, Sulfuric Acid.
The vented cable termination end is specially prepared at the factory to eliminate the potential for
moisture migration. Where the lead wires emerge from under the jacket, there’s potting material and
a shrink tube “boot”, every effort should be made to leave this feature intact. Should the cable be
longer than needed for the installation, it is recommended that the excess length be accommodated in
a service loop and that the potted end of the cable NOT be shortened.
The cable attached to this instrument is specifically engineered for submersible applications. The
polyurethane outer jacket provides long term reliability under most conditions. The cable should be
handled carefully, however, as the jacket may be subject to cutting should it be “raked” over extremely
sharp edges. To guard against water incursion should an inadvertent minor cut occur, we have
incorporated an exclusive “water block” feature immediately beneath the jacket. The cable is fully
shielded, with the shield connected to the metal housing at the transducer end and terminated in a
drain wire at the termination or user end. The shield should always be terminated to a good earth
ground, unless the transducer is installed in an area where galvanic corrosion is known to be a
serious problem.
Lightning Protection
Lightning and surge protection for VDC and 4-20 mA output are available. This is achieved through
the use of 2 protectors, one is integral to the transducer housing and one is provided for the outside
line located at the surface and grounded to a DIN-Rail. Please remember this option must be factory
installed at the time of order entry or as a factory upgrade. This option cannot be installed in the
field. Lightning protection is also available for unit only. Contact customer service for details.
Featuring quick response and low clamping voltages, these devices protect against fast rising voltage
transients as well as severe current surges associated with lightning discharges up to 20,000
amperes. Following a surge, the protector automatically restores the line to normal operation and
awaits the next surge without having to reset a breaker or replace a fuse. The power supply needs to
be limited to 150 mA to avoid lock up of the gas tube after a suppression event. If a lock-up should
occur, this is reset by disconnecting and reconnecting power to the circuit.
Transducers installed with this option have a two year warranty against damage due to voltage
surge.
Please note: When using the lightning protection option on 4-20 mA products, users should
take into account the additional series resistance of this option when selecting the loop power
supply. This option will increase total loop resistance by 88 Ohms, so the supply voltage must
be at least 12VDC when lightning protection is installed.

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 7 of 31 1-800-745-8008
W[email protected]
Electrical Outputs
We offer the industry standard 0-5 VDC and 4-20 mA outputs. In addition we also offer a variety of
voltage output ranges.
Cable Hanger
We can supply an optional cable hanger (P/N 12-90-0931) to help end users secure the cable. The
cable hanger can be positioned anywhere on the cable by pushing the ends together. Once
positioned, the cable hanger expands and provides a snug grip on the cable.
When mounting the transducer in a well casing, the cable hanger can be secured to a hook on the
well plate or an eye bolt may be attached to the side of the well casing. The cable hanger loop is then
secured to the eye bolt by using any number of types of fasteners. A similar technique can be used
when working in stilling wells for surface water level measurement. In this case, the loop- end of the
cable hanger can be attached directly to a screw or bolt bored into the still well shelf.
Submersible Cable Splicing Kit
Our field-installable cable splice kit (P/N 830) allows you to splice polyurethane and ETFE
submersible cable. It is most commonly used for well applications where the more expensive ETFE
cable is required for suspension in corrosive media where the liquid level is fairly shallow, but the well
is hundreds of feet in depth. It is also used in emergency situations where cable must be spliced
together to get an application up and running.

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 8 of 31 1-800-745-8008
W[email protected]
3.0 Installation & Maintenance Tips
WARNING: POTENTIAL ELECTROSTATIC CHARGING HAZARD
In hazardous locations:
● Avoid building up static charge on case of data protector and plastic accessories.
● Use damp rag to wipe data protector and plastic accessories to avoid static build up.
General Installation Procedures
The following is important installation and preventive maintenance information. Our Customer Service
or Applications Engineering Support staff can provide additional instruction.
Transducer Anchors:
Most users either suspend our submersible transducers in stilling wells or attach them to rigid conduit.
This is done to prevent damage to the transducer from shock caused by water turbulence. It is not
advisable to tie your transducer to a pump or to piping, as any problem with the transducer could
require that the pump be pulled from the installation. This could prove to be very expensive. (Please
refer to the Cable Anchoring Schemes drawing in Appendix A.)
Some applications use our optional bracket (P/N 49-06-00PC) to clamp the transducer to a fixed
object (i.e., wall, ladder, step) or require the unit to be suspended without any protective still well or
attachment device. In all installations, care should be taken to ensure no damage occurs to the cable.
Transducer Submersion:
Damage to submersible cable is one of the most frequent causes of transducer failure. Lower your
transducer into the liquid slowly, making sure the cable does not drag over sharp edges and only to
the depth necessary. Avoid dropping the unit from the surface.
SuperDry™ Vent Filter (Desiccant) or Aneroid Bellows Installation:
(For submersible transducers vented gage pressure format only)
Always install a desiccant vent filter or aneroid bellows immediately after transducer installation.
Failure to use one or the other could result in premature failure of the transducer; which would not be
covered by warranty. If you use a desiccant filter, you should establish a regular maintenance
schedule. You should change your vent filter when it is 75% spent (pink color). Replacement filters
are available at a nominal cost from the factory. Do not remove the old vent filter until a new one is
available. The most common failure mode of our transducers is moisture and corrosion damage due
to lack of use or maintenance of the vent filter. This will allow air into the desiccant filter and allows
the transducer to properly vent with changes in barometric pressure.

User Manual
MEAS LT Level & Pressure Transducer User Manual
Measurement Specialties, Inc. www.meas-spec.com 1-757-766-1500
1000 Lucas Way, Hampton, VA 23666 USA 9 of 31 1-800-745-8008
W[email protected]
To install/replace either the aneroid bellows or the vent filter, simply unplug the old unit from the vent
tube and plug the 0.062" x 1" stainless steel connector tube (supplied with each filter or bellows) into
the vent tube. (Installation and mounting instructions are supplied with each aneroid bellows and vent
filter.) The diagram on page 16 shows typical vent filter and aneroid bellows hookups.
Cable Protection:
An inexpensive way to protect the cable from damage is to order the submersible pressure transducer
with a ½" conduit attachment. If further protection is needed, connect an inexpensive flexible 5/8"
garden hose to the ½" conduit fitting with an inexpensive female PVC ½" NPT x 3/4" NHT swivel
fitting, available at your local hardware store. These options are not supplied by MEAS.
Bending of Cable:
Our polyurethane and ETFE jacketed cables are quite flexible. Care needs to be taken to ensure that
when bending the cable to suit your installation you do not crimp the vent tube inside the cable.
Consequently, do not bend the cable more than a radius of 1 inch.
Cable Compression:
Many users require a compression fitting to secure our ETFE and polyurethane jacketed cable as it
enters a junction box. Care needs to be taken that you do not over-tighten the fitting so as to damage
the cable. Compression fittings are not supplied by MEAS.
4-20 mA Wiring:
When connecting a 2-wire 4-20 mA transducer to a typical power supply and mA meter, verify that the
meter has an input impedance of at least 10 Ohms. If you are unsure of the input impedance, then a
10 Ohm resistor may be placed in series with the meter and transducer. Connect the + (red) lead of
the transducer to the + terminal of the power supply. If the 10 Ohm resistor is required, connect it to
the - (black) lead of the transducer. Use a short length of 22 AWG or heavier wire to connect the +
terminal of the meter to the resistor (if it is required) or the - (black) wire of the transducer. Connect
the - terminal of the meter to the - terminal of the power supply with a length of 22AWG or heavier
wire. Connect the drain wire from the transducer to a good earth ground. (See Appendix A, page 13
for wiring diagram.) Please refer to “Maximum Cable Lengths and Minimum Supply Voltage” in
Appendix C, page 19 to verify minimum loop supply voltage requirements.