Working principle of electromagnetic flowmeter: It is a kind of meter that measures the volume flow of conductive liquid by using 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.
The two electromagnetic coils at the end produce a constant magnetic field. When a conductive medium flows, an induced voltage is generated, which is proportional to the flow rate of the fluid, thereby obtaining a flow rate value Q.
The measuring tube of the flow meter is a non-magnetic alloy short tube lined with insulating material. The two electrodes are fixed to the measuring tube through the tube wall in the diameter direction. The electrode tip is substantially flush with the inner surface of the liner. When the exciting coil is excited by the two-wave pulse, an operating magnetic field having a magnetic flux density B is generated in a direction perpendicular to the axis of the measuring tube. At this time, if a fluid having certain conductivity flows through the measuring tube. The cutting magnetic field lines induce the electromotive force E. The electromotive force E is proportional to the magnetic flux density B, and the product of the inner diameter d of the measuring tube and the average flow velocity v.