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

Abstract

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.

Description

technical field [0001] The invention belongs to the technical field of fluid detection, and relates to an online verification / calibration method and device for an open channel flowmeter. Background technique [0002] As an instrument for measuring sewage flow, open channel flowmeters are widely used in industrial and urban wastewater discharge monitoring and measurement. Liquid level transmitters are often used in combination with flow tanks (Parshall tanks) and flow weirs (thin-walled weirs) as flow measurement devices. The accuracy of its flow measurement depends on the measurement accuracy of the liquid level transmitter and the geometric structure size, machining accuracy and flow integration formula of the flow groove or flow weir. Since the accuracy of sewage discharge measurement will directly affect the economic benefits of enterprises and society, it is necessary to install a sewage flow detection instrument that meets the requirements for each pollution discharge d...

AI Technical Summary

Problems solved by technology

Developed countries have advanced technology, and the open channel sewage flow monitoring system can be used for many years after one-time completion. However, due to various reasons in China, the open channel flowmeters installed by enterprises have not played their due role well. The actual sewage There are still many problems in the measurement and calibration of open channel measurement instruments, mainly reflected in: (1) After the flowmeter is installed, due to aging, fouling, failure and other reasons, the accuracy and reliability of the measurement data are reduced, which does not meet the requirements of the national standard. The requirements of measurement laws, regulations and standards; (2) Due to the limitation of detection technology, open channel sewage flowmeters cannot be regularly verified or calibrated online at present, and unqualified equipment cannot be found and updated in time; (3) Open channel flowmeters are used in sewage measurement The more prominent problem is that the instrument is verified or calibrated before installation, and it is generally impossible to disassemble it after it is put into use, and it is also impossible to carry out regular verification on it. The data obtained by monitoring is only an estimated value, which seriously affects social benefits.

[0003] Aiming at the current situation that the open channel flowmeter cannot be verified or calibrated for a long time after it is put into operation and cannot be verified online, a new online verification / calibration method for open channel flowmeters has been invented, and an online verification / calibration device has been developed.

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