Reduce costs and simplify instrumentation at treatment plant headworks. The DLT 2.0 can measure both differential level plus flow through a flume. Install one Sensor on each side of a mechanical barscreen to continuously monitor, transmit and control level. Use the built-in control relays or 4-20mA outputs to automatically activate the barscreen rake at preset levels.
The DLT 2.0 is a simple solution for barscreen level control at wastewater treatment plants, pump stations and combined sewer systems. It includes two non-contacting ultrasonic sensors to measure level. With sensors positioned above a channel, up and downstream from the barscreen, the DLT 2.0 can display and transmit differential level. The downstream sensor can also be installed above a flume or weir to measure and totalize open channel flow.
Three 4-20mA outputs are configured to transmit upstream level, downstream level (or flow) and differential level. Built-in relays can be calibrated for level control, differential level control or open channel flow.
Other DLT 2.0 applications include two-tank inventory where you can monitor level in two tanks with one instrument. The DLT 2.0 will alternate display of level in both tanks plus transmit 4-20mA outputs. Use the built-in relays to activate alarms or level controls. This versatile dual-sensor instrument can also be configured as a submergence alarm for Parshall flumes.
Contact Greyline Instruments for specific recommendations in your application.
DIFFERENTIAL LEVEL TRANSMITTER SPECIFICATIONS
SCOPE:This specification covers a non-contacting ultrasonic Differential Level Transmitter as manufactured by Greyline Instruments, Massena New York / Long Sault, Ontario. This instrument shall provide for indicating, transmitting and control of level, barscreen differential level and open channel flow through a flume, weir, or other primary measuring device.
GENERAL
- Differential Level Transmitter to consist of two non-contacting ultrasonic sensors, 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 length shall be as required by installation, not to exceed 500 ft (152 m).
- System shall have no moving parts and shall not contact the material being measured.
SENSING ELEMENT
- Ultrasonic sensors shall be constructed of PVC.
- Sensors shall have a minimum deadband or blanking of 8" (203.2 mm) and a maximum range of 15 ft. (4.57 m), and have an operating frequency of 92 kHz with an ultrasonic beam angle of 8 Degrees.
- Sensors shall withstand accidental submersion to 20 psi (1.4 bar).
- Sensor operating temperature shall be from -40°F to 150°F (-40°C to 65°C).
- Sensors shall include integral temperature sensor. Temperature sensors requiring separate mounting and wire runs shall not be accepted.
SENSOR CONNECTING CABLE
- Provide RG62AU coaxial cable 25' (7.6m) continuous length, with waterproof, potted bond to the Sensor head.
- Extended sensor cable shall be RG62AU coaxial to a maximum of 500' (152m) for each sensor. 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.
TRANSMITTER
- The transmitter shall include a built-in 5-Key calibration system with operator selection of parameters through visual prompts from a Menu calibration system. Systems requiring calibration by Parameter codes 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 selection and automatic conversion of measurement units, measurement span and control relays.
- The transmitter shall provide for field calibration in user-selected Level, Range and/or Open Channel Flow modes. Operation mode shall be user-selectable for differential level, differential level plus open channel flow, level/volume in two tanks or submerged flow alarm in Parshall flumes.
- Transmitter shall permit field programmable damping to smooth output in turbulent level conditions and to disregard false signals from waves and spurious echoes.
- Transmitter electronics operating temperature shall be from -5° to 140°F (-20° to 60°C).
- Transmitter shall have three isolated 4-20mA outputs each with 1000 ohm maximum load. Outputs shall allow field programmable offsets of 4mA and 20mA for level, differential level and open channel flow.
- Provide 2 control relay dry contacts rated 5 ampere SPDT. Relays shall be programmable for level alarm, differential level control, temperature alarm, pump control, pump alternation, flow totalizer pulse and/or echo loss alarm.
- Provide a white, backlit matrix LCD display indicating level, differential level, flow rate, totalizer and relay states in user-selected engineering units.
- Transmitter shall be housed in a wall-mount, watertight NEMA4X (IP 66) enclosure with hinged, clear cover. Mounting hardware shall be included.
- Transmitter LCD display shall be visible without opening cover.
- Transmitter electronics shall include automatic high voltage bleeds for nearby lightning strikes.
- Electronics shall be modular and field replaceable by means of plug-in circuit boards. The instrument shall detect and load software menus automatically for field-installed options.
- The transmitter shall be powered by 100-240VAC 50/60Hz requiring less than 3 Watts.
OPTIONAL FEATURES FOR INSERTION AS REQUIRED
- Have 4 additional (6 total) control relays, rated 5 amp SPDT and programmable for level alarm, differential level control, temperature alarm, pump control, pump alternation, flow totalizer pulse and/or echo loss alarm.
- 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.
- Have a thermostat controlled enclosure heater for Transmitter operation at temperatures below freezing.
- Have two PZ34T non-contacting ultrasonic PVC sensors rated for measurement range up to 32 ft (10 m) with minimum deadband or blanking of 16" (406 mm).
- Have manufacturer's recommended enclosure sunscreen to permit Transmitter mounting in direct sunlight.
- Have manufacturer's recommended Sensor sunscreen to permit temperature-compensated Sensor mounting in direct sunlight.
- Have manufacturer's recommended Panel Mount Flange assembly for enclosure installation.
- Have a built-in 2 million point Data Logger with USB output to flash drive or mass storage device.
- Transmitter power input shall be 9-32VDC with maximum power consumption of 3 watts or less.
MANUFACTURER
- DLT 2.0 Differential Level Transmitter shall be Model DLT 2.0 as manufactured by Greyline Instruments Inc. and shall be warranted against defects in materials and workmanship for one year.
