Electrode polarization problem of electromagnetic flowmeter

The electromagnetic flowmeter has no flow display, which can be restored after power failure. If there is a large polarization voltage between the two electrodes, it can be judged that the electrode polarization causes the so-called polarization because there are excessive positive or negative charges on the relative electrodes, resulting in a strong capacitance effect and causing the current to not pass normally. That is, the electrode potential deviates from the equilibrium potential when the current passes. The

electrode polarization of the electromagnetic flowmeter is generally not caused by material problems, but by the excitation method. If the electromagnetic flowmeter uses DC excitation, the medium flow rate is slow, and the medium has a tendency to corrode, the possibility of polarization is high. The three-value low-frequency rectangular wave excitation technology (with a period of 1/8 of 50Hz and a sinusoidal excitation current) can eliminate the polarization interference of the DC magnetic field. It has better zero point stability and solves the influence of interference potential.

In this case, the appropriate brand and model of electromagnetic flowmeter should be selected, the flow rate should be appropriately increased, and of course, it is also important to choose the correct electrode material.