LEVEL INDICATING TRANSMITTER SPECIFICATIONS
SCOPE: This specification covers a non-contacting, ultrasonic Level Indicating Transmitter as manufactured by Greyline Instruments Inc., Largo, Florida / 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.
A. PERFORMANCE SPECIFICATIONS
- To consist of a non-contacting ultrasonic sensor, connecting cable, and a remote enclosure with indicating, transmitting and controlling electronics.
- Measurement accuracy shall be ±0.25% of Range or 2 mm (0.08"), whichever is greater, and shall be automatically temperature compensated.
- Sensor cable shall be RG62AU coaxial with total length as required for installation, not to exceed 500 ft (152 m).
- System shall have no moving parts and shall not contact the material being measured.
B. NON-CONTACTING SENSOR
- Sensor shall be constructed of PVC and Teflon.
- 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 8ø.
- Sensor shall withstand accidental submersion to 20 psi.
- Sensor operating temperature shall be from -40°F to 150°F (-40°C to 65°C).
- Sensor shall include integral temperature sensor. Temperature sensors requiring separate mounting and wire runs shall not be accepted.
C. SENSOR CONNECTING CABLE
- Provide RG62AU coaxial cable 25 ft (7.6 m) continuous length, with waterproof, potted bond to the Sensor head.
- 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.
- Level and temperature signals shall be conducted on one single coaxial cable. Separate or multiple-conductor cables shall not be accepted.
- Sensor cable shall be installed in grounded metal conduit.
D. INDICATING TRANSMITTER
- 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.
- 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.
- 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.
- Calibration data shall be permanently stored through power interruptions without requirement of a back-up battery.
- Field calibration shall allow keypad selection of measurement span, Range or Level operating modes, and display units in Percent, Inches or Centimeters.
- 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.
- Transmitter operating temperature shall be from -13°F to 122°F (-25°C to 50°C).
- Transmitter shall have an isolated 4-20mA output into a 1000 ohm maximum load. Output shall allow field programmable offsets of 4mA and 20mA.
- Provide one signal relay contact rated 1 amp. Relay shall be programmable for single set point alarm, pump control, and/or echo loss alarm.
- Transmitter electronics shall be surge protected on AC power input, sensor and 4-20 mA output.
- Transmitter power input shall be 120VAC 50/60Hz with power consumption of 5 Watts or less.
E. ADDITIONAL FEATURES FOR INSERTION IN SPECIFICATION AS REQUIRED:
- Transmitter power input shall be 200-250VAC 50/60Hz with maximum power consumption of 5 watts or less.
- Transmitter power input shall be 24VDC with maximum power consumption of 5 watts or less.
- Have an all-PVC ultrasonic sensor model PZ34 rated for 32 ft (10 m) maximum range and designed for pump station applications.
- Have an all-Teflon sensor model PZ32TE rated for 32 ft (10 m) maximum range and operation from -40°F to 170°F (-40°C to 76°C).
- Have a PVC and Teflon sensor model PZ56 rated for measurement range on liquids up to 50 ft (15.6 m).
- Have a Teflon-faced flange mount sensor model PZ34TxF rated for 32 ft (10 m) measurement range. Specify flange size of 4” or 6”.
- Include manufacturer's recommended sensor cable Junction Box for extended cable lengths.
- 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.
F. MANUFACTURER
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.
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