How to debug the electromagnetic flowmeter

Electromagnetic flowmeter debugging:

Fluidic liquids containing uniformly distributed fine air bubbles usually do not affect normal measurements, but when the measured volumetric flow is the sum of both liquid and gas, the output signal fluctuates due to the increase in air bubbles, if the air bubbles are large enough to flow over the electrodes to cover the entire electrode surface , Make the electrode signal circuit break instantaneously, the output signal will produce greater fluctuation.

When two or more liquids are used as a pipe mixing process, if the conductivity of the two liquids (or their respective electrode chapter potentials) is different, the flow sensor will enter the flow measurement before the mixing is not uniform, and the output signal will also fluctuate.

Low-frequency (50/16~50/6Hz) rectangular excitation electromagnetic flowmeters will produce slurry noise when the solid content in the liquid exceeds a certain level, and the output signal will also fluctuate to a certain extent.

The poor matching of the electrode material and the measured medium produces chemical effects such as passivation or oxidation. The formation of an insulating film on the surface of the electrode, as well as electrochemical and polarization phenomena, will interfere with the normal measurement.

Pipeline systems and installations are usually faults caused by improper installation of electromagnetic flowmeter sensors. Commonly, flow sensors are installed at the high point of pipe network where accumulation of entrapped gas is common; the back pressure of the flow sensor directly discharges the liquid into the atmosphere. The formation of its non-full pipe inside the measuring pipe; installed in the vertical pipe from top to bottom, there may be emptying and other reasons.

The main aspects of the environment are stray currents in the pipeline, electromagnetic interference in the space, and magnetic interference in large electrical machines. The stray current interference of the pipeline is usually obtained by taking good individual grounding protection to obtain a satisfactory measurement, but if there is a strong stray current in the pipeline (such as a pipeline in the electrolysis workshop), it may not be overcome, and the measure of insulation between the flow sensor and the pipeline must be adopted. Space electromagnetic interference is usually introduced via signal cables. Usually single-layer shielding is used for protection. However, shielding protection has not yet been overcome.