Common alarm faults of electromagnetic flowmeters

Case introduction

A brief analysis of common alarm faults of electromagnetic flowmeters:

1. No display on the electromagnetic flowmeter

1. Check whether the power supply is connected; 2. Check whether the power fuse is intact; 3. Check whether the power supply voltage meets the requirements ; 4. Check whether the display contrast adjustment can be adjusted and whether the adjustment is appropriate; 5. If the first three items above are normal and the fourth item, the display contrast adjustment cannot be adjusted, please send the instrument to the manufacturer for repair.

2. Electromagnetic flowmeter excitation alarm

1. Whether the excitation wiring EX1 and EX2 are open circuit; 2. Whether the total resistance of the sensor excitation coil is less than 150Ω; 3. If both a and b are normal, the converter is faulty;

3. Electromagnetic flowmeter Empty pipe alarm

1. Measure whether the fluid fills the sensor measuring tube; 2. Use wires to short-circuit the converter signal input terminals SIG1, SIG2 and IGGND. At this time, if the empty pipe alarm prompt is cancelled, it means that the converter is normal and it may be The measured fluid conductivity is low or the empty pipe threshold and empty pipe range are set incorrectly; 3. Check whether the signal connection is correct; 4. Check whether the sensor power is normal; ① Make the flow rate zero, and observe that the conductivity ratio should be less than 100% ② In When there is flow, the resistance of terminals SIG1 and SIG2 to SIGGND measured respectively should be less than 50KΩ (measured value for the medium is water. Use a pointer multimeter to measure, and you can see that there is a charge and discharge circuit phenomenon during the measurement process). 5. Use a multimeter to measure the DC voltage between DS1 and DS2 and it should be less than 1V. Otherwise, it means that the sensor circuit is contaminated and should be cleaned.

4. The upper limit alarm of the electromagnetic flowmeter indicates that the output current and output frequency (or pulse) exceed the limit. Increasing the process range can cancel the upper limit alarm.

5. The electromagnetic flowmeter lowers the limit alarm. The lower limit alarm prompts that the output current and output frequency (or pulse) exceed the limit. Changing the flow range to a smaller value can cancel the lower limit alarm.