Open channel flowmeter, according to the different measurement principles, is divided into ultrasonic open channel flowmeter and Doppler open channel flowmeter, they are all in the open channel or channel measurement of fluid flow system monitoring equipment. Open channel flowmeter monitoring system, suitable for reservoir, river, water conservancy project, urban water supply, sewage treatment, farmland irrigation, water resources and other rectangular, trapezoid open channel and culvert flow measurement. It has been widely used in recent years.
Ultrasonic open channel flowmeter
Using open channel technology, based on the flow-water level calculation method, the flow rate is obtained by measuring the fluid level height, combining the geometric size of the standard weir groove, slope coefficient, channel accuracy, hydraulic ramp, vertical plane correction coefficient of the flow rate, and then calculating through the microprocessor inside the instrument. Due to non-contact measurement, open channel flowmeters can be used in harsh environments. Under the control of the microcomputer, the open channel flowmeter transmits and receives the ultrasonic wave, and calculates the distance between the open channel flowmeter and the measured liquid surface according to the transmission time, so as to obtain the liquid level height. Because there is a certain proportional relationship between the liquid level and the flow rate, the liquid flow rate Q can be obtained according to the calculation formula.
Doppler open channel flowmeter
The contact measurement method is adopted, the sensor is placed at the bottom of the channel, and between the two probes, the system calculates the outflow velocity according to the Doppler time effect, and then converts the instantaneous flow through the cross-sectional area of the sensor area according to the formula.
Post time: Aug-07-2023