What is the reason why electromagnetic flow meters cannot be used for distilled water?

Case introduction

1. Working principle of electromagnetic flowmeter

Electromagnetic flowmeter is an instrument for measuring the flow of conductive liquid. By installing a pair of electrodes above the pipe, a magnetic field is introduced into the pipe. When the conductive liquid is in When flowing in the pipeline, the electromotive force generated and the electromotive force induced by the magnetic field form an alternating electric field, which is the effect of the law of electromagnetic induction. According to Ampere's theorem, the flow rate can be calculated by measuring the induced voltage between the electrodes.

2. Characteristics of Distilled Water

Distilled water is water that has been processed through the distillation process. It has high purity, no oxygen, no salt, no suspended solids, and almost no impurities. . Therefore, the conductivity of distilled water is extremely low, and the working principle of the electromagnetic flowmeter is based on the conductivity of the liquid. Liquids with low conductivity will greatly affect the measurement accuracy of the electromagnetic flowmeter.

3. Reasons why electromagnetic flowmeter cannot be used for distilled water

Since the conductivity of distilled water is very low, when using an electromagnetic flowmeter, the induced voltage between the measuring electrodes is relatively small. , easily affected by electromagnetic interference, and because there are not enough ions in the distilled water liquid, the effect of the law of electromagnetic induction will also be weakened due to the greater impact of sufficient ions. This will lead to instability and increased errors in the electromagnetic flowmeter measurement values, affecting the precision and accuracy of the measurement.

To sum up, the conductivity of distilled water is too low, which will greatly affect the measurement accuracy of the electromagnetic flowmeter, so the electromagnetic flowmeter cannot be used to measure distilled water. In actual use, other measuring instruments suitable for the characteristics of distilled water should be used to ensure the accuracy and stability of the measurement.