Common faults of electromagnetic flowmeters and their solutions

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Common faults of electromagnetic flowmeters and their solutions 1. No display on the electromagnetic flowmeter’s gauge 1. Check whether the power supply is connected； 2. Check whether the power fuse is intact ； 3. Check whether the supply voltage meets the requirements. II. Electromagnetic flowmeter excitation alarm 1. Check whether the excitation connections E*1 and E*2 are open circuit ； 2. Check whether the total resistance of the sensor excitation coil is less than 150Ω ； 3. If both of the above items are normal, then the converter is faulty. III. Alarm for empty tube in electromagnetic flowmeter 1. Check whether the fluid being measured fills the sensor’s measuring tube ； 2. Short-circuit the converter’s signal input terminals SIG1, SIG2, and SIGGND using a wire. If the “empty tube” warning is removed at this point, it indicates that the converter is functioning properly; the low conductivity of the fluid being tested or an incorrect setting for the empty tube threshold may be the cause ； 3. Check whether the sensor electrodes are functioning properly ； 4. Set the flow rate to zero, and observe that the conductivity ratio should be less than 100% ； 5. When current is flowing, the resistance between terminals SIG1T and SIG2 to SIGGND should be less than 50 KΩ (the values are measured with water as the dielectric; it is advisable to use an analog multimeter for measurement, and charging and discharging phenomena can be observed during the measurement process) ； 6. The DC voltage between DSI and DS2, as measured with a multimeter, should be less than 1V; otherwise, it indicates that the sensor electrodes are contaminated and need to be cleaned. IV. Inaccurate flow measurement by electromagnetic flowmeters 1. Check whether the fluid being measured fills the sensor’s measuring tube ； 2. Check whether the signal cable connections are proper ； 3. Check whether the sensor coefficients and zero points are set according to the sensor label or the factory calibration sheet.