| 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 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 PZ52T 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”, 6”
or 8”.
- 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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