The measurement principle of the electromagnetic flowmeter is based on Faraday's electromagnetic induction principle law: when the conductive liquid moves to cut the magnetic line of force in the magnetic field, the conductor will generate an induced electric potential, and its induced electric heat E is: E=KBVD

Where: k ------ instrument constant B ------ magnetic induction V ------ average flow velocity in pipe section D ------ inner diameter of pipe section

The electromagnetic flowmeter is applicable to measuring the volume flow of conductive liquid and slurry in closed pipes, such as clean water, sewage, various acid, alkali and salt solutions, mud, pulp, pulp and food liquids.

Selection Guide 

When measuring the flow, the conductive liquid flows through the magnetic field perpendicular to the flow direction at the speed V, and the flow of the conductive liquid induces a voltage proportional to the average flow rate. The induced voltage signal is detected by two or more electrodes that directly contact the liquid, and sent to the converter through cables for intelligent processing. Then the LCD displays or converts it into a standard signal of 4~20mA and 0~1kHz for output.

The selection of instruments is a very important work in the application of instruments. According to relevant data, 2/3 of the failures of instruments in practical application are caused by incorrect selection and installation of instruments. Pay special attention. Collect data ① Name of the measured fluid; ② Maximum flow, minimum flow; ③ Maximum working pressure; ④ Maximum temperature, minimum temperature. The measured fluid must have certain conductivity, with conductivity ≥ 5 μ  S/cm。 The maximum flow and minimum flow must conform to the values in the following table. (The process range is extended to 0.1~15m/s). It is recommended to determine the caliber by 70% of the upper and lower limits. The actual maximum working pressure must be less than the rated working pressure of the flowmeter. The maximum and minimum operating temperatures must meet the temperature requirements specified by the flowmeter. Determine whether there is negative pressure. You can select the corresponding electromagnetic flowmeter according to the flow rate in the above table. If the internal diameter of the selected electromagnetic flowmeter is inconsistent with the internal diameter of the process pipe, the pipe shall be shrunk or expanded. If the pipe is shrunk, consider whether the pressure loss caused by pipe shrinkage will affect the process flow. Considering the product price, electromagnetic flowmeter with smaller diameter can be selected to reduce investment. When measuring the clean water, the economic flow rate is 2~3m/s. When measuring the solution that is easy to crystallize, the flow rate should be increased appropriately to prevent the electrode of the electromagnetic flowmeter from being covered.