Open channel flow meter is commonly used to measure flow rates in irrigation channels, streams, storm water systems and wastewater processing for monitoring the effluent discharge.
Open channel flow meter includes a non-contacting sensor mounted above the flume or weir (eg: parshall flume, rectangular weir, V-Notch weir, etc.). Weirs and flumes concentrate the flow into a known cross-sectional area, relating an accurate level reading to an accurate flow rate. The height of the water in the channel, going over the weir or flume, is directly proportional to the flow rate.
- Flumes generate upstream liquid level height changes indicative of flow rate. One of the most common flume designs is the Parshall flume.
- Weirs are a fixed obstruction across a channel where the liquid passes. As the flow passes over the crest and drops into the downstream channel it is accelerated. Rectangular weir has a notch of simple rectangular shape, as the name implies. V-notch weir has a triangular notch, customarily measuring either 60 or 90 degrees.
Flumes are generally less accurate than weirs, but they have the advantage of being inherently self-cleaning. If the liquid stream being measured is drainage or wastewater, solid debris in the flow could cause repeated clogging problems for weirs. In such applications, flumes are often the more practical flow element.
The UOL series is a non-contact ultrasonic open channel flow meter, with low blind area, high sensitivity, and high stability. It consists of ultrasonic sensor and a wall-mounted converter, complete with display and integral keypad for programming. The UOL series is mainly used for measuring water conservancy irrigation, sewage plants, urban sewage, chemical factory and other industries.
- Probe range: 0 to 3m (Standard), 0 to 6m (option), 0 to 12m (option)
- Accuracy: ±0.2% F.S (In air)
- Analogue output: 4-20mA (0-500Ω)
- Relay output: 6 SPDT (5A / 250V AC / 30V DC)
- Serial communication: RS485 with Modbus-RTU (standard protocol)
- Temperature range: -40 to 70˚C
- Power supply: 24V DC (±5%) 0.2A / 220V AC (±20%) 0.1A
- Cable length: 10 meter (extendable to 1000 meter)
BAMOSONIC
Bamosonic is a high-performance ultrasonic transmitter with integrated transducer and electronic processing module. Compact, this transmitter is powered by the loop (4-20 mA; 2-wire) and stands out for its reliability and high accuracy. With a US beam angle of 6° it is perfectly suited for open channel flow measurement on exponential section channels.
- Measuring range: Up to 4m (upper dead zone of 20cm)
- Resolution: < 2 m: 1 mm; from 2 to 4 m: 2 mm
- Accuracy: ± (0,2% of measured distance + 0,05% of range) Under optimal operating conditions and stabilized temperature
- Liquid temperature: -30 to +90 °C
- Ambient temperature: -25 to +70 °C
- Beam measuring angle: 6˚
- Power supply: 12 to 36 V DC; 48 to 720 mW
- Output signal: 4-20 mA, 2-wires
