The working principle of the plug-in 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. Two electrodes inside the pipe measure the induced voltage generated. The measurement pipeline is electromagnetically isolated from the fluid and the measurement electrode through a non-conductive lining (rubber, PTFE, etc.).