Instrument Mesurement Knowledge

What Factors Affect the Accuracy of Electromagnetic Flow Meters?

Views: 15     Author: Site Editor     Publish Time: 2021-08-26      Origin: Site

Electromagnetic flowmeter is a specific system composed of transmitter and converter. Insulation, number of shielding layers, distributed capacitance and cross-sectional area of conductor will all affect the measurement results of electromagnetic flowmeter.

Improper selection

The electrode and the lining are materials in direct contact with the medium. If we choose inappropriate electrode and liner materials, it will cause many problems, such as electrode scaling and corrosion, lining wear, scaling and deformation. These problems will lead to inaccurate measurement of industrial flowmeter and shorten the service life of magnetic flowmeter.

Unstable excitation method

A. DC wave excitation 

DC excitation is prone to electrode polarization and DC interference. Too high polarization voltage will block the input of the converter, and the converter of magnetometer can't amplify the normal signal. Therefore, we can't receive the reading displayed by the magnetic flowmeter.


B. AC sine wave excitation

AC sine wave excitation is easy to cause zero point vibration of electromagnetic flowmeter. Obviously, improper zero position will lead to inaccurate measurement.