Avoid these mistakes when using electromagnetic flowmeter

Electromagnetic flowmeters are characterized by high precision and long life, and are used in many fields and industries such as chemical industry, environmental protection, and metallurgy. However, during use, due to the influence of many factors, it is easy to cause inaccurate measurement results of electromagnetic flowmeters. So what are the causes of errors in electromagnetic flowmeters?

1. The tube is not filled with liquid

Due to insufficient back pressure or poor installation position of the flow sensor, the liquid in the measuring tube cannot be filled. The fault phenomenon has different manifestations depending on the degree of infilling and flow conditions.

If a small amount of gas flows in a water pipe in a stratified or wavy flow, the fault phenomenon is manifested as an increase in error, that is, the flow measurement value does not match the actual value;

If the flow is a bubble flow or a plug flow, the fault phenomenon is not only that the measured value does not match the actual value, but also the output shakes due to the gas phase momentarily covering the electrode surface;

If the gas phase part of the flow cross-sectional area in the horizontal pipeline stratified flow increases, that is, the degree of liquid not filling the pipe increases, the output sloshing will also occur;

If the liquid is not filling the tube seriously, so that the liquid level is below the electrode, the output will be overfull.

2. Liquid contains solid phase

When the liquid contains solids such as powder, particles or fibers, the following faults may occur: ① slurry noise; ② electrode surface contamination; ③ conductive or insulating deposits covering the electrode or lining; ④ the lining is worn or covered by deposits, resulting in a reduction in the flow cross-sectional area.

3. Electromagnetic flowmeters should be used with caution for liquids that may crystallize

Some chemical materials that are easy to crystallize can be measured normally under normal temperature conditions. Since the conduits that convey the fluid have good heat tracing and insulation, they will not crystallize during the insulation work. However, it is difficult to implement heat tracing and insulation on the measuring tube of the Figurines electromagnetic flow sensor. Therefore, when the fluid flows through the measuring tube, it is easy to cause a layer of solid to form on the inner wall due to cooling.

Since the crystallization problem also exists when using flowmeters based on other principles, in the absence of other better methods, an "oring" electromagnetic flow sensor with a very short measuring tube can be used, and the upstream pipeline of the flowmeter should be heated and insulated. In terms of pipeline connection methods, the flow sensor should be easy to disassemble and install, so that it can be easily removed for maintenance in the event of crystallization.

4. Problems caused by improper selection of electrode and grounding ring materials

The parts of the Figurines electromagnetic flowmeter that are in contact with the medium include electrodes and grounding rings. In addition to corrosion resistance problems, improper matching can also cause electrode surface effects.

I hope that through the editor’s introduction to the causes of errors in electromagnetic flow meters, everyone can have a deeper understanding of electromagnetic flow meters, and can use electromagnetic flow meters correctly to avoid errors.