Your position: Home > News

The Reason for Measurement Error of the Electromagnetic Flowmeter

2019-01-10
 The Reason for Measurement Error of the Electromagnetic Flowmeter
 
The main effects of electromagnetic flowmeter errors can be divided into three categories: 
 
improper selection, influence of test liquid and interference
 
 
1. The flow rate of the liquid to be tested The flow rate of the electromagnetic flowmeter is 
 
generally 0.5 to 10 m/s, and the economical flow rate is 1.5 to 3 m/s. In actual use the inner 
 
diameter of the measuring tube is determined according to the flow rate to be measured and the 
 
flow rate range of the electromagnetic flowmeter.
 
 
2. Electrode and lining material selection electrode and lining material are directly in  
 
contact with the liquid to be tested, and should be based on the characteristics of the liquid  
 
to be tested (such as corrosiveness, abrasion, etc.)And the working temperature selection

electrode and lining material, if improperly selected, it will cause problems such as fast adhesion,

corrosion, scaling, abrasion, lining deformation,which in turn produces measurement errors.
 
 
3. Excitation stability The excitation mode of electromagnetic flowmeter is DC excitation, AC 
 
sine wave excitation and dual-frequency rectangular wave excitation. DC excitation is easy to 
 
generate.Electrode polarization and DC interference problems, AC sinusoidal excitation is easy

to cause zero point variation, and dual-frequency rectangular wave excitation has excellent low-
 
frequency rectangular wave excitation.Zero stability. In practical applications, the stability of the

power supply voltage and frequency should be ensured as much as possible to ensure that the

magnetic field strength is constant and the magnetic field strength is reduced.Measurement error
caused by theization.

 

share:

Pre:DN1500mm Q&T Instrument electromagnetic flow meter
Next: Maintenance Knowledge of Electromagnetic Flowmeter