LEVEL INDICATING TRANSMITTER SPECIFICATIONS
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.
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
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
- 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
- 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
(10 m) maximum range and operation from -40°F to 170°F (-40°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,
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