Engineering Specifications
Level Indicating Transmitter
Greyline LIT25


SCOPE: This specification covers a non-contacting, ultrasonic Level Indicating Transmitter as manufactured by Greyline Instruments Inc., Massena, New York / Long Sault, Ontario. The instrument shall provide for indicating, transmitting and control of the material level in a vessel, or proximity of a target to the Instrument Sensor.


  1. To consist of a non-contacting ultrasonic sensor, connecting cable, and a remote enclosure with indicating, transmitting and controlling electronics.
  2. Measurement accuracy shall be 0.25% of Range or 2 mm (0.08"), whichever is greater, and shall be automatically temperature compensated.
  3. Sensor cable shall be RG62AU coaxial with total length as required for installation, not to exceed 500 ft (152 m).
  4. System shall have no moving parts and shall not contact the material being measured.


  1. Sensor shall be constructed of PVC and Teflon.
  2. The sensor shall have a minimum deadband or blanking of 12" (305mm) and a maximum range of 32 ft (10 m), and have an operating frequency of 42 kHz with an ultrasonic beam angle of 8.
  3. Sensor shall withstand accidental submersion to 20 psi.
  4. Sensor operating temperature shall be from -40F to 150F (-40C to 65C).
  5. Sensor shall include integral temperature sensor. Temperature sensors requiring separate mounting and wire runs shall not be accepted.


  1. Provide RG62AU coaxial cable 25 ft (7.6 m) continuous length, with waterproof, potted bond to the Sensor head.
  2. Extended sensor cable shall be RG62AU coaxial to a maximum of 500 ft (152 m). Cable shall be spliced with screw terminal connections in manufacturer's recommended steel NEMA4 Junction Box.
  3. Level and temperature signals shall be conducted on one single coaxial cable. Separate or multiple-conductor cables shall not be accepted.
  4. Sensor cable shall be installed in grounded metal conduit.


  1. The Indicating Transmitter shall be housed in a wall-mount, watertight NEMA4X (IP66) enclosure with clear, polycarbonate cover. Mounting hardware shall be included. Combined Transmitter/Sensor systems requiring mounting at the top of a tank shall not be accepted.
  2. Transmitter shall include a large 4-digit LCD display with 3/4" (19 mm) high digits that shall be visible without opening the enclosure cover.
  3. The transmitter shall provide for field-calibration via built-in 2-key calibration system. Systems requiring calibration by BCD switches or external calibrators shall not be accepted.
  4. Calibration data shall be permanently stored through power interruptions without requirement of a back-up battery.
  5. Field calibration shall allow keypad selection of measurement span, Range or Level operating modes, and display units in Percent, Inches or Centimeters.
  6. Transmitter shall permit field programmable damping to smooth output in turbulent level conditions, and programmable rejection time to disregard false signals from agitators, waves and spurious echoes.
  7. Transmitter operating temperature shall be from -13F to 122F (-25C to 50C).
  8. Transmitter shall have an isolated 4-20mA output into a 1000 ohm maximum load. Output shall allow field programmable offsets of 4mA and 20mA.
  9. Provide one signal relay contact rated 1 amp. Relay shall be programmable for single set point alarm, pump control, and/or echo loss alarm.
  10. Transmitter electronics shall be surge protected on AC power input, sensor and 4-20 mA output.
  11. Transmitter power input shall be 120VAC 50/60Hz with power consumption of 5 Watts or less.


  1. Transmitter power input shall be 200-250VAC 50/60Hz with maximum power consumption of 5 watts or less.
  2. Transmitter power input shall be 24VDC with maximum power consumption of 5 watts or less.
  3. Have an all-PVC ultrasonic sensor model PZ34 rated for 32 ft (10 m) maximum range and designed for pump station applications.
  4. Have an all-Teflon sensor model PZ32TE rated for 32 ft (10 m) maximum range and operation from -40F to 170F (-40C to 76C).
  5. Have a PVC and Teflon sensor model PZ56 rated for measurement range on liquids up to 50 ft (15.6 m).
  6. Have a Teflon-faced flange mount sensor model PZ34TxF rated for 32 ft (10 m) measurement range. Specify flange size of 4 or 6.
  7. Include manufacturer's recommended sensor cable Junction Box for extended cable lengths.
  8. Sensor, connecting cable and junction boxes shall be rated intrinsically safe to Class I,II,III, Div. I,II, Groups C,D,E,F,G.


The instrument shall be a Model LIT25 Ultrasonic Level Transmitter as manufactured by Greyline Instruments Inc., and warranted against defects in materials and workmanship for one year.

Specifications are subject to change without notice. 

Sensor Mounting Recommendations and Drawings for Level Applications
How to Extend Sensor Cable
Back to LIT25 Description
Back to Greyline Instruments Product List

Please contact Greyline if you need more information or for advice in your application. We can provide quotations and refer you to the Greyline sales representative in your area. (To receive complete information please provide your name, mailing address, phone and fax numbers):

Greyline Instruments Inc.
16456 Sixsmith Drive
Long Sault, Ont. K0C 1P0
Tel: 613-938-8956 / 888-473-9546
Fax: 613-938-4857
Greyline Instruments Inc.
105 Water Street
Massena, NY 13662
Tel: 315-788-9500 / 888-473-9546
Fax: 315-764-0419