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How to maintain electromagnetic flowmeter introduction

What do we need to pay attention to when using electromagnetic flowmeters? Today, we will make a brief explanation for everyone. I hope everyone will pay attention to the following points regarding the maintenance of electromagnetic flowmeters:

1, routine maintenance

Only need to periodically check the instrument, check the environment around the instrument, remove the dirt, ensure that no water and other substances are inspected, check whether the wiring is good, check whether there is a new strong electromagnetic field device near the instrument or a new wire across the instrument.

2, fault finding

After the electromagnetic flowmeter starts to be put into operation or is put into normal operation for a period of time, it is found that the instrument is not working properly. First, check the external condition of the flowmeter, such as whether the power supply is good, whether the pipeline leaks or is in a state of non-full pipe, whether there are air bubbles or signal cables in the pipeline. Whether it is damaged or not, the converter output signal is open. Remember to blindly disassemble the flowmeter.

3, sensor inspection

Test equipment: one 500MΩ insulation resistance tester, one multimeter.

Test steps:

1) When the pipeline is filled with medium, measure the resistance between terminals A, B and C with a multimeter. The resistance between A-C and B-C should be equal. If the difference is more than 1 time, there may be leakage of the electrode, condensation on the outer wall of the measuring tube or the junction box.

2) In the case of lining drying, measure the insulation resistance between A-C and B-C with MΩ meter (should be greater than 200MΩ). Then use a multimeter to measure the resistance of the two electrodes in terminals A and B and the measuring tube (should be in short-circuit communication). If the insulation resistance is small, indicating that the electrode is leaking, the entire flowmeter should be returned to the factory for repair. If the insulation is reduced but there is still more than 50 MΩ and the inspection result of step (1) is normal, the outer wall of the measuring tube may be damp, and the inside of the outer casing may be dried by a hot air blower.

3) Use a multimeter to measure the resistance between X and Y. If it exceeds 200 Ω, the excitation coil and its lead wire may be open or poorly connected. Remove the terminal block check.

4) Check the insulation resistance between X, Y and C, which should be above 200 MΩ. If it is lowered, dry the inside of the case with hot air. In actual operation, the decrease in coil insulation will result in increased measurement error and unstable instrument output signal.

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