Application Of Electromagnetic Flowmeter in Water Industry

The working principle of electromagnetic flowmeter is based on Faraday's law of electromagnetic induction. In the electromagnetic flowmeter, the conductive medium in the measuring tube is equivalent to the conductive metal rod in the Faraday test, and the two electromagnetic coils at the upper and lower ends generate a constant magnetic field. When a conductive medium flows through, an induced voltage will be generated (the working principle is shown in the figure below). Two electrodes inside the pipe measure the induced voltage generated. The measuring pipeline is electromagnetically isolated from the fluid and the measuring electrode through a non-conductive lining (rubber, Teflon, etc.). The functions of electromagnetic flowmeters on the market are quite different. The simple one is to measure one-way flow, and only output analog signals to drive the rear-position meter; multi-function meters have two-way flow measurement, range switching, upper and lower limit flow alarms, empty pipes and power cut off. Alarm, small signal removal, flow display and total calculation, automatic check and fault self-diagnosis, communication with upper computer and motion configuration, etc. The serial digital communication function of some models of instruments can choose a variety of communication interfaces and special-purpose chips (ASIC) to connect to the HART protocol system, PROFTBUS, Modbus, FF fieldbus, etc. Electromagnetic flowmeter has a series of excellent characteristics, which can solve the problems that other flowmeters are not easy to apply, such as the measurement of dirty flow and corrosive flow. In the 1970s and 1980s, there was a major technological breakthrough in electromagnetic flow, and its application was very extensive.