Open channel flowmeter

summary:

Working principle of ultrasonic open channel flowmeter: The larger the flow rate in the open channel, the higher the liquid level; The smaller the flow rate, the lower the liquid level. For general channels, there is no definite correspondence between liquid level and flow rate. Because the same water depth and flow rate are also related to the cross-sectional area, slope, and roughness of the channel. Installing a measuring weir groove in the channel, the correspondence between the upstream water level and flow rate of the channel mainly depends on the geometric dimensions of the weir groove, as the gap of the weir or the contraction of the groove is smaller than the cross-sectional area of the channel. The same measuring weir tank is placed on different channels, and the same liquid level corresponds to the same flow rate. The measuring weir channel converts the flow into liquid level. By measuring the liquid level of the water flowing through the measuring weir, the flow rate can be calculated based on the water level flow relationship of the corresponding measuring weir. Common types of measuring weirs and channels.

Principle of Ultrasonic Liquid Level Measurement: This instrument uses ultrasonic echo ranging method to measure liquid level. The probe is fixedly installed above the water level observation point of the measuring weir (the location of the water level observation point can be found in the weir structure description).

The probe emits ultrasonic waves, which are then reflected by the liquid surface and received by the probe. The distance between the probe and the liquid (object) surface is proportional to the time the ultrasonic waves have passed

H= CT/2 ; Distance [m]=Time x Sound Speed/2 [m]

Temperature compensation formula for sound velocity: Environmental sound velocity=331.51+0.61 x temperature

The ultrasonic open channel flowmeter is controlled by the instrument probe to emit and receive ultrasonic waves. Convert to liquid level (unit: meter) according to the process in Figure 8. Then, by checking the water level flow meter, convert the liquid level into flow rate (which can be expressed in liters per second or cubic meters per hour).

A water level flow meter is a set of data stored in an instrument. You can input data into the instrument's memory through the buttons on the instrument panel. The water level flow meter of this instrument is stored at equal liquid level intervals. The position of "cumulative traffic reset time" is displayed.

Main technical indicators and parameters:

Scope of application:

Used in conjunction with a measuring weir to measure the flow rate of water in an open channel. It is mainly used to measure the flow rate and irrigation channels of sewage treatment plants, enterprise liquid units' sewage discharge outlets, urban sewers, etc.

Basher trough (Basher trough)

material6-12mm thick PVC and fiberglass. The larger the flow rate, the corresponding increase in wall thickness.