The non contact open channel flowmeter is cheap and easy to operate, so it is used to measure the flow rate of sewage.It is worth noting that the open channel flow meter is different from other closed full tube flow meters in that it can better monitor the flow rate of liquid in non-full tube state or in open channel measurement.

As is known to all, the principle of non contact open channel flow meter is placed in channel standard measuring weir trough (e.g., flume bashir's), was measured by flow fluid height, then through measuring instrument internal processor operation get traffic (according to corresponding flow formula or empirical formulae, the measured water level value converted to flow).According to the statistics, the majority of the open channel measurement methods are the bachelle channel open channel flowmeter.In addition, the repeatability of liquid level measurement in open channel flowmeter mainly depends on the stability of liquid level.In the actual measurement of sewage, water flow is often unstable, such as the generation of small whirlpools, waves, foam, etc., and the repeatability of liquid level measurement is often not more accurate.

Even so, non contact open channel flowmeter is still one of the common flowmeters in sewage treatment.