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Electromagnetic flowmeter working principle

Apr 07, 2017

Electromagnetic flowmeter working principle:
The  electromagnetic flowmeter is suitable for measuring the volume flow of  conductive liquid and slurry in a closed pipe. Its working principle is  based on Faraday's law of electromagnetic induction: when a conductor  moves in the magnetic field, the conductor in the direction  perpendicular to the direction of the magnetic field and the direction  of motion The  magnitude of the electromotive force is proportional to the size of the  conductor's velocity and the magnetic induction intensity of the  magnetic field. The electromagnetic flowmeter consists of a transmitter and a converter. The transmitter (also known as the sensor) is based on Faraday's law of electromagnetic induction. The  principle is shown in the following figure: The measuring tube is  equipped with an excitation coil up and down, and the two  electromagnetic coils at both ends of the upper and lower excitation  current generate a constant magnetic field. When the measured medium  (ie, the conductive medium in the measuring tube) flows perpendicularly  to the magnetic field line Induction  potential Ex; a pair of electrodes mounted on the measuring tube wall  and liquid contact, lead the induced voltage, sent to the converter. In recent years, with the deepening of theoretical technology, people  in the design and manufacture, in the measurement of the electrode plane  to add two ground electrode, so no need to add a grounding ring can  eliminate electrical noise interference.