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Multiple electromagnetic flowmeters were used in the gasification unit. The faults encountered during its commissioning were as follows: 1. Sudden drop in flow signal or no indication. Process operators reported that the flow value indicated by the flowmeter for the ash water coming out of the circulating ash water cooler dropped suddenly. Based on years of experience in instrument maintenance, it was determined that the main cause of this issue was deterioration of the insulation between the electrodes or a short circuit, which prevented the signal from being transmitted. After a careful inspection, it was found that the signal socket was corroded; it was cleaned with clean water and dried, and after being reinstalled, it worked properly. Of course, in addition to the reasons mentioned above, it’s also possible that there is dirt buildup on the inner wall of the measurement catheter, or that the lining of the measurement catheter has been damaged; the specific cause determines the appropriate solution. 2. Fluctuations in the output signal During routine inspections, the technicians noticed that the output signal of the electromagnetic flowmeter was experiencing severe fluctuations. After checking to ensure that there were no fluctuations or pulsations in the fluid being measured, and that the pipes were filled with liquid, it was determined that there was no fault with the electromagnetic flowmeter itself. It was discovered that a technician nearby was welding a joint, and it was concluded that the electromagnetic interference was caused by the operation of the welding machine; once the source of this interference was removed, the flowmeter’s readings returned to normal. 3. Unstable zero point During process shutdown, the zero point of the thick slurry flow meter was unstable. Inspection revealed that there was dirt deposited inside the pipe measured by this meter, attached to the inner walls of the measuring tube, which caused fluctuations in the zero point of the electromagnetic flow meter. After removing the dirt from the electrodes and their vicinity, the zero point still showed some instability. After recalibrating it using a BT200, the meter began to function normally. Of course, in addition to the reasons analyzed above, there may be four other reasons for zero-point instability: the pipeline is not filled with liquid or there are bubbles in the liquid ； Is there a leak in the pipeline? ； Is there any impact from external electromagnetic interference? ； 4. The measurement value of the electromagnetic flowmeter does not match the actual value. Even after ensuring that the liquid in the pipeline being measured fills the sensor and is at rest, and after recalibrating the zero point of the meter using a BT200, there is still a discrepancy between the measured value and the actual value. Upon careful inspection, it was found that the range setting of the converter was incorrect; after resetting it to the correct range for that meter, the readings became normal. Other possible causes for this discrepancy include improper installation of the sensor, insufficient liquid in the pipeline, or the presence of bubbles in the liquid being measured. Such issues are mainly due to poor design of the pipeline system, as well as inadequate quality of related equipment ； The insulation capacity of the signal cable has decreased. First, conduct a joint verification on-site with the control room to confirm whether the cable connections are correct, and then check whether the wiring terminals or cable joints are damp, which could reduce the cable’s insulation capacity ； The flow conditions upstream of the sensor are not satisfactory. The flow conditions upstream of the sensor are often restricted by space constraints, failing to meet the required standards. For example, in the case of electromagnetic flowmeters, there may not be a long enough straight pipe section adjacent to the elements that cause turbulence; such conditions can affect the accuracy of measurements. Accumulations on the inner wall of the measurement tube or wear on the tube walls can also change the flow area, thereby affecting the measured values ； Changes in the resistance between the sensor electrodes or a decrease in electrode insulation. This fault is often caused by rainwater entering the terminals and causing them to become damp. Insulation can be restored by removing moisture. For more information, please visit the company’s official website at http://www.yb1518.com/. Please keep this link when reproducing the content! http://www.yb1518.com/UploadFiles/2012717174126829.jpg