How to maintain the electromagnetic flowmeter when it is shut down?

Case introduction

Electromagnetic flowmeters should also pay attention to maintenance when they are not used. This is because the meter will malfunction if it is not used for a long time. We know that instruments and meters have a service life. Instruments will wear out during use. Reasonable maintenance can not only extend the service life of instruments and meters, but also improve the accuracy of measurement, which has far-reaching significance for instruments and meters. The following is a brief introduction to the maintenance of the electromagnetic flowmeter when it is shut down.

When the electromagnetic flowmeter is shut down and not in use, we must adopt scientific and reasonable maintenance methods for the electromagnetic flowmeter. When providing electromagnetic flowmeter technical services to users, it is often encountered that after users purchase the electromagnetic flowmeter and use it for a period of time, they find that the measurement data is inaccurate when they use it again. In fact, this is not a quality problem with the electromagnetic flowmeter itself. Because the user did not follow the after-use care and maintenance methods in the instruction manual.

1. Regularly check the electrical performance of the sensor during 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 roughly the same. Record the resistance value measured for the first time. This value will be useful for later 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 megger 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

2. Electromagnetic flowmeter Maintenance zero point inspection and adjustment:

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, the flow should also be stopped regularly for zero checks based on the operating conditions; especially for sedimentation, easy-to-contaminate electrodes, and non-cleaning fluids containing solid phases, more inspections should be carried out in the early stages of operation to gain experience and determine the normal inspection cycle. The electromagnetic flowmeter with AC excitation method is more likely to produce zero point drift than the rectangular wave shock ratio, so more attention should be paid to inspection and adjustment.