Analysis of common alarm failure of electromagnetic flowmeter

1.Electromagnetic flow meter doesn’t display

A.Check if the power supply is connect;

B.Check that the power fuse is in good condition;

C.Check if the supply voltage meets the requirements;

D.Check if the display contrast adjustment can be adjusted, and if the adjustment is appropriate;

E.If the above three items are all normal, the fourth item of the display contrast adjustment can not adjust, send the instrument to the production factory maintenance.

2.Electromagnetic flowmeter excitation alarm

A.Check if the field coil EX1 and EX2 are open circuit;

B.Check if the total resistance of field coil is less than 150Ω;

C.If A, B are all normal, then the converter is faulted.

3.Electromagnetic flow meter empty pipe alarm

A.Check if the measuring liquid full of measuring tube of the sensor;

B.Connect the converter signal input terminal SIG1, SIG2 and IGGND with cable to make them short circuit, if the empty pipe alarm cancel, then the converter is in normal condition, it might be the measured liquid has low conductivity or the atc threshold and atc range setup error.

C.Check if the signal wiring is correct.

D.Check if the sensor electrodes normal

Make the flow be zero, Observation shows that the conductance ratio should be less than 100%

In the condition of there is flow in pipe, measuring the resistance between SIG1 and IGGND and between SIG2 and IGGND respectively should be less than 50KΩ(the medium is water, it is better to use pointer multimeter, and could observe there is charging and discharging phenomenon during the measuring).

E.Use the multimeter measure direct voltage between DS1 and DS2 should be less than 1V, or else the sensor electrodes are polluted, should be cleanout.

4.Electromagnetic flow meter upper limit alarm

The upper limit alarm indicates that the output current and output frequency (or pulse) are over limit, the upper limit alarm can be cancelled by enlarging the flow range.

5.Electromagnetic flow meter lower limit alarm

The lower limit alarm indicates that both the output current and output frequency (or pulse) are out of limit, the lower limit alarm can be cancelled by reducing the flow range.