Electromagnetic flowmeter can not measure the liquid which

Liquids that cannot be measured by electromagnetic flowmeters include pure water, deionized water, ultrapure water, organic solvents, petroleum products, etc. 

The electromagnetic flowmeter is a flow measurement instrument based on Faraday's law of electromagnetic induction. It calculates the flow rate by measuring the induced electromotive force generated by the movement of conductive liquid in a magnetic field. However, electromagnetic flowmeters have their own scope and limitations, and for some specific types of liquids, their measurement results are not ideal. Specifically, electromagnetic flowmeters are not suitable for measuring the following types of liquids:

Liquids containing a large amount of gas: If the liquid contains a large amount of gas, such as stratified flow, corrugated flow, bubble flow or plug flow , the measurement accuracy of the electromagnetic flowmeter will be affected, and the output may shake or exceed fullness due to the gas phase momentarily covering the electrode surface.

Organic solvents: Organic solvents usually have low conductivity, and electromagnetic flowmeters are not effective in measuring liquid media with very low conductivity.

Deionized water and ultrapure water: Due to their extremely low conductivity, these liquids are not suitable for measurement by electromagnetic flow meters.

Petroleum products: including diesel, gasoline, etc. These liquids are usually non-conductive, and electromagnetic flowmeters require the measured medium to have a certain conductivity to accurately measure.

In addition, electromagnetic flowmeters are not suitable for measuring steam and liquids containing a large amount of gas, because these conditions will cause the liquid in the measuring tube to fail to be filled, thus affecting the accuracy of the measurement. When choosing to use an electromagnetic flowmeter, appropriate selection and adjustment must be made according to the characteristics of the liquid being measured to ensure the accuracy of the measurement results.