Method and device for carrying out online verification/calibration on open channel flowmeter

The invention discloses a method and device for carrying out online verification/calibration on an open channel flowmeter. The device comprises a measurement control system, a flow velocity meter, a liquid level transmitter, a screw rod, a guide rod and a bracket. The device has a simple structure, and is used for measuring the flow of an open channel by adopting a velocity and area method. A system automatically selects characteristic points to be measured according to structure parameters of the open channel, the flow is obtained through computation and is compared with flow data of the flowmeter to be calibrated, thus the purpose of verification/calibration is achieved. By adopting the invention, the problem of incapability of carrying out online calibration and incapability of verification or calibration for a long time after the open channel flowmeter is put into operation is solved, thus the metering precision of the open channel flowmeter is increased, and the emission of industrial sewage is effectively monitored.