Electromagnetic flowmeter sensor inspection method

Case introduction

Sensor inspection method of electromagnetic flowmeter

As an instrument used within the flow measurement range, electromagnetic flowmeter is loved by many industrial enterprises. As a professional manufacturer of electromagnetic flowmeters, In the process of providing customers with installation and maintenance for many years, the company has summarized a complete set of methods and techniques for the maintenance of electromagnetic flowmeters.

Testing equipment required: a multimeter and a 500MΩ insulation resistance tester.

Test and inspection steps:

(1) When the pipe is filled with medium, use a multimeter to measure the resistance between terminals A, B and C, and between A-C and B-C The resistance values ​​should be large enough to be equal. If the difference is more than 1 time, it may be due to electrical leakage or condensation water adsorption on the outer wall of the measuring tube or in the junction box.

(2) When the lining is dry, use a MΩ meter to measure the insulation resistance between A-C and B-C (should be greater than 200MΩ). Then use a multimeter to measure the resistance of terminals A and B and the two currents in the measuring tube (they should be in a short-circuit state). If the insulation resistance is very small, it indicates electrical leakage, and the entire flow meter should be returned to the factory for repair. If the insulation has declined but is still above 50MΩ and the inspection result in step (1) is normal, the outer wall of the measuring tube may be damp, and a hot air blower can be used to dry the inside of the casing.

(3) Use a multimeter to measure the resistance between X and Y. If it exceeds 200Ω, the excitation coil and its lead wire may be open circuit or have poor contact. Remove the terminal board and inspect.

(4) Check the insulation resistance between X, Y and C. It should be above 200MΩ. If it drops, use hot air to dry the inside of the shell. During actual operation, the reduction in coil insulation will lead to increased measurement errors and unstable instrument output signals.

(5) If it is determined that the sensor is faulty, please contact the electromagnetic flowmeter manufacturer. Generally, it cannot be solved on site and needs to be repaired by the manufacturer.