How to maintain the electromagnetic flowmeter before shutdown?

Regularly check the electrical performance of the sensor for electromagnetic flowmeter maintenance:

First, roughly measure the resistance between the electrodes. Disconnect the signal connection between the sensor and the converter. The sensor is filled with liquid. Use a multimeter to measure the resistance value of the two electrodes and the ground terminal to see if it is within the value range specified by the manufacturer, and the two measured values ​​are approximately the same. Record the resistance value measured for the first time. This value is useful for determining the cause of sensor failure, such as whether the deposited layer is conductive or insulating. Secondly, drain the liquid out of the sensor, wipe the inner wall, and after it is completely dry, use a megohmmeter to measure the resistance between the two electrodes and the ground terminal. Finally, check the insulation resistance of the excitation coil, remove the sensor excitation coil, connect the terminals to the converter, and measure the insulation resistance of the coil with a megohmmeter.

Zero point check and adjustment for electromagnetic flowmeter maintenance:

Before the electromagnetic flowmeter is put into operation, the zero point must be adjusted when the electromagnetic flow sensor is filled with liquid and is stationary after being powered on. After being put into operation, it is also necessary to stop the flow regularly for zero checks according to the operating conditions; especially for sedimentation, easy-to-contaminate electrodes, and non-clean liquids containing solid phases, more inspections should be made in the early stages of operation to obtain experience to determine the normal inspection cycle. Electromagnetic flowmeters that change the excitation method and the rectangular wave shock ratio are more likely to produce zero point drift, so careful inspection and adjustment are required.