The electromagnetic flowmeter is the flowmeter based on Faraday's law of electromagnetic induction. The advantage of electromagnetic flowmeter is that the pressure loss is very small and the range of measurable flow is large. The ratio of maximum flow to minimum flow is more than 20:1. Applicable industrial diameter range, maximum up to 3m, output signal and measured flow linearity, high accuracy, can measure conductivity ≥5μs/cm acid, alkali, salt solution, water, sewage, corrosive liquid and slurry, pulp, and other fluid flow. But it cannot measure the flow of gas, steam, and pure water.