1. Failure during operation
Operation faults are those that occur after the electromagnetic flowmeter has been debugged and operated normally for a period of time. Common operating faults are basically caused by the adhesion layer on the inner wall of the flow sensor, lightning strikes and changes in environmental conditions.
2. Adhesion layer on inner wall of sensor
Since electromagnetic flowmeters are often used to measure dirty fluids, after a period of operation, adhesion layers often accumulate on the inner wall of the sensor and cause malfunctions. These failures are often caused by too much or too little conductivity of the adhesion layer. If the attachment is an insulating layer, the electrode circuit will be open and the meter will not work normally; if the conductivity of the attachment layer is significantly higher than the fluid conductivity, the electrode circuit will be short-circuited.
The meter also does not work properly. Therefore, the adhesion fouling layer in the measuring tube of the electromagnetic flowmeter should be removed in time.
3. Thunder strike
Lightning strikes are likely to induce high voltage and surge current in the meter circuit, causing damage to the meter. It is mainly introduced through the power line or the excitation coil or the flow signal line between the sensor and the converter, etc., especially from the control room power line.
4. Changes in environmental conditions
During the commissioning period, due to good environmental conditions (for example, no interference source), the flowmeter works normally, and it is easy to neglect the installation conditions (for example, the grounding is not very good). In this case, once the environmental conditions change, a new source of interference appears during operation (such as electric welding on the pipeline near the flowmeter, installation of a large transformer nearby, etc.), which will interfere with the normal operation of the meter and the output of the flowmeter. The signal will fluctuate.