Open channel flowmeter uses an ultrasonic sensor with a Parshall groove to measure open channel flow. Ultrasonic open channel flowmeter is composed of 3 parts: level sensor, water measuring sink and flow totalizer.

Ultrasonic Open Channel Flowmeter

Ultrasonic open channel flowmeters are used to measure the flow of fluids in non-full tubular open channels and natural flowing water surfaces. It is called open channel flow detection. The measuring flume that is not full is called an open channel. The open channel flowmeter measures the water level in the measuring weir trough, and then calculates the flow rate according to the water level flow relationship of the corresponding measuring weir trough.

Features of Ultrasonic Open Channel Flowmeter

  • Ultrasonic non-contact liquid level measurement does not affect the flow rate at all. Accurate liquid level measurement is an ideal level meter.
  • The probe has low power consumption, simple installation and easy positioning. It is widely used in rivers, water supply, factories, urban sewage pipelines and other related fields.
  • The flow totalizer is easy to operate and suitable for wide types of water measuring weirs, including thin-walled right-angled triangular weirs, rectangular weirs, and Parshall grooves.
  • The flow totalizer has the function of historical flow recording. It can record the flow data of the past 60 hours, 30 days, 12 months, and 10 years. More historical data can be recorded in real time through the SD card.
  • Comprehensive instrument control functions, four-way relay signal output, easy to connect to commonly used actuators (motors, alarms, etc.).
  • According to the requirements of working conditions, the probe can choose special models such as IP68, anti-corrosion, explosion-proof, small blind area high-precision, ultra-low power consumption, large range and other special models.
  • Built-in remote communication module, various communication protocols can be customized (customized when ordering).

Specifications of Ultrasonic Open Channel Flowmeter

StructureOne-piece and split type
Measuring range0.1m³/h~99999.99m³/h is determined according to different weirs and troughs
Cumulative flowThe maximum is: 429000000.00m3
Level measurement accuracy0.50%
Resolution3mm or 0.1% (whichever is greater)
Flow measurement accuracyStandard weirs and troughs 1~5% (weir troughs and channels that meet the requirements of the national standard),
non-standard weirs and troughs 10~50%
powered by220VAC±15% 50HZ, or 24VDC 120mA, (optional) 12VDC,
battery powered, solar powered
Protection levelDisplay instrument IP66, probe IP68
Probe selection instructionsIt is recommended to use 100KHz M48×2 probe for No.1-5 Parshall grooves,
The measuring range is 1 meter, it is not easy to hit the wall or corner of the Parshall groove to form false signals;
The probe blind area is small, only 10-13 cm, and the mounting bracket can be made lower;
It is recommended to use 64Khz M48×2 probe for No. 6-25 Parshall slot, measuring range 2 meters, blind area 30 cm.

Parshall groove (PVC material, stainless steel material) for Open Channel Flowmeter

Ultrasonic Open channel flow meter working principle

The open channel flowmeter is based on the specific shape of the Parshall metering groove/weir plate metering groove. It guarantees a certain liquid level and knows a certain flow rate. The Parshall groove/weir plate metering groove is selected as the specific flow channel. The measurement accuracy is high. Easy to install.

The sensor measures the height of the liquid level, which is processed by 89C52 series single-chip microcomputers to obtain the instantaneous flow and cumulative flow values.

The flow can be expressed by the following formula:
  Q: Instantaneous flow rate (t/h) K: Flow rate constant
  H: height of liquid level n: nth power value

The instantaneous flow is processed by the cumulative accumulation to obtain the cumulative flow.

Application of ultrasonic open channel flowmeter:

Due to the non-pressure flow characteristics of open channel flow meters, they are widely used in sewage discharge outlets. It is suitable for the measurement and control of wastewater from various enterprises such as chemical industry, metallurgy, environmental protection and pharmaceutical.

Ultrasonic Open Channel Flowmeter measures sewage

Because the ultrasonic open channel flowmeter uses open channel non-contact measurement. Therefore, the probe can be separated from the host. It can effectively solve the problems of probe corrosion and instrument accuracy, so it is widely used in irrigation and drainage and sewage measurement.

Ultrasonic Open Channel Flowmeter measures sewage.jpg

Note when installing:

  • To ensure that the sewage flowing through the flow tank has no foreign matter. A filter must be installed not far upstream of the flow tank;
  • To ensure that the sewage flowing through the flow tank is stable and without ripples. A still water well connected to the flow trough can be arranged on the side of the flow trough. The inner diameter of the well is ≥100mm. The bottom of the well should be 150mm below the lowest point of the trough. The width of the straight section of the trough ≥ 10 times the width of the water surface of the weir. The highest water level downstream is lower than the lowest water level of the weir;
  • The emission surface of the sensor probe should be parallel to the liquid surface. The distance between the lower end of the sensor and the highest liquid level should be ≥0.7 m;
  • There should be no strong light, electromagnetic field and other radiation sources around the sensor;
  • There should be measures to prevent rain and snow above the ultrasonic sensor.

Note in use:

  • Because the places where sewage ultrasonic sensors are installed are places with relatively poor environment. Therefore, the host of the instrument should be installed indoors. There should be a dedicated person to take care of it. Conduct regular inspections of lines and sensors;
  • The meter should be checked regularly.

Read more about: Waste water measurement

More Featured Ultrasonic Flow Meter

Sino-Inst, Manufacuturer for Open Channel Flowmeters. It can measure a single sound-conducting liquid medium. It can measure even liquids such as water, sea water, oil, and slurry.

Sino-Inst’s Open Channel Flowmeter, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, US, and other countries.

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Please provide your measurement parameters or details. Sino-Instrument support customer customization and OEM
Please provide your measurement parameters or details. Sino-Instrument support customer customization and OEM

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