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Methods For Correctly Detecting And Finding Electromagnetic Flowmeter Faults And It's Solution

Author:vacorda    Source:www.vacorda.com    Date: 2020-04-27 14:38:45
As one of the most widely used instruments in the flow measurement range, electromagnetic flowmeters are commonly used to measure conductive liquids such as tap water, sewage, and seawater. Therefore, after a period of operation, it is easy to contaminate the electrode or deposit or scale in the measuring tube wall. The scale layer attached to the measuring tube of the electromagnetic flowmeter should be removed in time, otherwise the meter will not work properly. As a professional manufacturer of electromagnetic flowmeters, 
Sichuan Vacorda Instrument Manufacturing Co., Ltd. has summarized a set of routine inspections of electromagnetic flowmeter sensors in the process of providing customers with installation and maintenance for many years. It is the most effective way to avoid malfunctions:

The most common situation we encounter is: the electromagnetic flowmeter starts to operate or it is found that the instrument is not working properly after a period of normal operation. If this happens, you should first check the external conditions of the flowmeter and determine whether the power supply Good, then check whether the pipeline is leaking or is not full, whether there are air bubbles in the pipeline, whether the signal cable is damaged, and whether the output signal of the converter (that is, the input circuit of the rear instrument) is open. Follow this correct procedure and remember to blindly disassemble the flowmeter.

Magnetic flowmeter sensor inspection
Test equipment to be prepared: a multimeter and a 500MΩ insulation resistance tester.
Test check steps:

(1) When the pipeline is full of medium, use a multimeter to measure the resistance between terminals A, B and C. The resistance between A-C and B-C should be large. If the difference is more than 1 time, there may be leakage of the electrode, condensation of water on the outer wall of the measuring tube or in the junction box.

(2) When the lining is dry, use an 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 between terminals A and B and the two electrodes in the measuring tube (should be in a short-circuit connection state). If the insulation resistance is very small, it means that the electrode is leaking, and the entire flowmeter should be returned to the factory for repair. If the insulation is reduced but still more than 50MΩ and the inspection result of step (1) is normal, the outer wall of the measuring tube may be damp, and the inside of the shell can be dried by a hot air fan.

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

(4) Check the insulation resistance between X, Y and C. It should be above 200MΩ. If it decreases, dry the inside of the shell with hot air. In actual operation, the decrease of the coil insulation will cause the measurement error to increase and the instrument output signal to be unstable.

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

Magnetic flowmeter converter inspection

If it is determined that the converter is faulty and there is no problem after checking the external cause, please contact the manufacturer of the electromagnetic flowmeter, and the manufacturer will generally take the solution of replacing the circuit board.

Maintenance of Electromagnetic Flowmeter Electrodes

1. Before using an electromagnetic flowmeter, first calibrate the electromagnetic flowmeter with a standard pH solution. After calibration, before operation, everyone must pay attention to cleaning the electrodes of the electromagnetic flowmeter with distilled water, and then cleaning the electrodes with the test liquid.

2. If you do not use an electromagnetic flowmeter, when you take off the electrode of the electromagnetic flowmeter, you must pay attention not to let the sensor of the electrode collide with a hard object, otherwise the use of the electrode will be affected if any damage occurs.

3. After using the electromagnetic flowmeter, you should cover the electrode of the electromagnetic flowmeter with a small amount of saturated solution in it, as long as the bulb of the electrode is moist, but you should not soak it in distilled water.

4. Usually pay attention to keep the electrode clean, do not let its two sides of the output appear short-circuited, otherwise it will make the measurement inaccurate and affect the use of the electromagnetic flowmeter.

What we introduce to you is just a very small part of our work. There are actually many ways to maintain the electrodes of the electromagnetic flowmeter. You should pay more attention and summarize in the process of use. After all, only through your own practice. The method summed up and explored is the most applicable. It is good to observe and analyze in the daily maintenance of production. The maintenance must be performed in accordance with this correct step. Do not damage the electromagnetic flowmeter because of a little negligence. , So that it cannot be used in the future. 

And if you cannot solve the problems, just feel free to call us directly, and we are glad to provide you with the solution.

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