Electromagnetic flowmeters are widely used in chemical, papermaking, food, textile, metallurgy, environmental protection, water supply and drainage and other industries due to their many advantages.
Electromagnetic flowmeter is an instrument that uses Faraday's law of electromagnetic induction to measure the flow of conductive fluid based on the electromotive force generated by the flow of conductive fluid cutting magnetic lines of force. Electromagnetic flowmeters are widely used in chemical, papermaking, food, textile, metallurgy, environmental protection, water supply and drainage and other industries due to their many advantages. In recent years, with the continuous improvement of production technology, higher requirements have been placed on the stability and reliability of various types of instruments while upgrading equipment. Of course, there will also be some faults in the use of electromagnetic flowmeters. For example, common faults include: no display on the meter, inaccurate flow measurement, empty pipe alarm (FGP), system alarm (SYS), upper and lower limit alarms (FQH FQL), etc. . UHMC Youheng Measurement and Control shares with you how to correctly handle flow meter failures.
(1) What to do if the electromagnetic flowmeter has no display?
First check whether the power supply is turned on, check whether the power fuse is intact, and finally check whether the power supply voltage meets the requirements of the electromagnetic flowmeter;
(2) How to deal with the excitation alarm?
Whether the excitation wiring EX1 and EX2 are open circuit; secondly, whether the total resistance of the sensor excitation coil is less than 150Ω; if both a and b are correct, consider the converter to be faulty.
(3) How to deal with air traffic control alarms?
① Check whether the measurement fluid is filled with the sensor measurement pipe. Use wires to short-circuit the converter signal input terminals SIGI, SIGI2 and SIGGND. At this time, if there is an empty pipe prompt to cancel, it means that the on-site converter is Normally, it may be that the conductivity of the fluid being measured is too low or there is an error in the empty pipe threshold and empty pipe range settings.
② In addition, check whether the signal connection is correct enough, and check whether the electrode of the sensor is normal: make the flow rate zero, and observe that the conductance ratio should be less than 100%. In the case of flow, it needs to be measured separately. The resistance of terminals SIGI and SIG2 to SIGGND should be less than 50kΩ (it is best to use a pointer multimeter to measure the value when the medium is water, and you can see re-discharge during the measurement process).
③Use a multimeter to measure the DC voltage between DS1 and DS2 and it should be less than 1V. Otherwise, it means that the electromagnetic flowmeter sensor has been contaminated and needs to be cleaned.
(4) How to deal with inaccurate measurement flow?
Check whether the measuring fluid is filled with the sensor measurement pipe;
In addition, check whether the signal line is normal, and check whether the sensor coefficient and sensor zero point are set according to the sensor label or factory calibration sheet.
The above are some minor problems that arise in the use of electromagnetic flowmeters in the industry. They are a summary of the judgments and treatment methods for faults encountered during the use of electromagnetic flowmeters. For an instrument maintenance personnel Generally speaking, mastering the troubleshooting of electromagnetic flowmeter is the guarantee for ensuring normal production.
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