Use electromagnetic flowmeter to avoid these errors
Electromagnetic flowmeters have the characteristics of high precision and long life, and are used in many fields and industries such as chemical industry, environmental protection, metallurgy, etc. However, in the process of use, due to the influence of various factors, it is easy to cause inaccurate measurement results of the electromagnetic flowmeter. So what are the causes of errors in electromagnetic flowmeters?
1. The liquid in the tube is not full
Due to insufficient back pressure or poor installation position of the flow sensor, the liquid in the measuring tube could not be filled, and the fault phenomenon has different performances due to the degree of underfill and flow conditions.
If a small amount of gas is stratified flow or wave flow in the water pipe, the fault phenomenon is shown 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, in addition to the measured value is not consistent with the actual value, the output will sway due to the gas phase covering the electrode surface instantly;
If the gas-phase part of the cross-sectional area of ??the horizontal pipeline in the stratified flow increases, that is, the degree of liquid underfill increases, output sloshing will also occur;
If the liquid is not full, the situation is more serious, so that the liquid level is below the electrode, and the output will be overfull.
2. The liquid contains a solid phase
The liquid contains powder, particles or fibers and other solids, and the possible faults are: ① slurry noise; ② contamination of the electrode surface; ③ conductive deposition layer or insulating deposition layer covering the electrode or lining; ④ the lining is worn or covered by deposits, The cross-sectional area of ??circulation was reduced.
3. For liquids that may crystallize, electromagnetic flowmeters should be used with caution
Some easily crystallized chemical materials can be measured normally under normal temperature conditions. Since the pipes conveying fluid have good heat tracing and heat insulation, they will not crystallize during the insulation work, but the measuring tube of the Figueres electromagnetic flow sensor is difficult to implement. Thermal insulation, therefore, when the fluid flows through the measuring tube, it is easy to cause a layer of solid on the inner wall due to cooling.
Since the flowmeter measurement using other principles also has the crystallization problem, in the absence of other better methods, an 'oring' electromagnetic flow sensor with a very short measurement tube length can be used, and the flowmeter The upstream pipeline heat insulation is strengthened. In the pipeline connection method, the flow sensor is considered to be easy to disassemble and install, and can be easily removed and maintained once it is crystallized.
4. Problems caused by improper electrode and ground ring material selection
Due to the mismatch between the material and the measured medium, the parts of the Figueres electromagnetic flowmeter that come into contact with the medium have electrodes and grounding rings. Improper matching, in addition to corrosion resistance, as long as the surface effect of the electrode.
I hope that through the introduction to the reasons for the errors of electromagnetic flowmeters, we can have a deeper understanding of electromagnetic flowmeters and use electromagnetic flowmeters correctly to avoid errors.
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