We need to adopt scientific and reasonable maintenance and maintenance methods for electromagnetic flowmeters. When downtime is not in use, many people find that after purchasing the electromagnetic flowmeter for a period of time, use the measured data again for inaccuracy. In fact, this is not a problem with the quality of the electromagnetic flowmeter itself. This is because the user did not follow the instructions in the manual for maintenance and maintenance. Sewing And Embroidery Machine,Chainstitch Embroidery Machine,Hat Stitching Machine,Innovis Sewing Machine Ningbo World Wide Electric techonology CO.,Ltd , https://www.ningbomachine.com
A, zero point inspection and adjustment of electromagnetic flowmeter maintenance
Before the electromagnetic flowmeter is put into operation, after the power is turned on, the zero point must be adjusted when the electromagnetic flow sensor is filled with liquid. After the start of operation, zero-point check shall be performed for the use conditions to stop the flow regularly; in particular, for precipitation and easy-to-pollution electrodes, non-clean liquids containing solid phases shall be inspected at the initial stage of operation to obtain experience and determine the normal inspection cycle. Exciting electromagnetic flowmeters and square wave impulse ratios are more likely to cause zero drift, so more attention should be paid to inspection and adjustment.
An example of an application error in which two deposition layers are faulty. One is the oil drilling cementing project, the total flow of injecting cement slurry is an important process parameter, often using high-pressure electromagnetic flowmeters. The meter is used intermittently. The sensor tube is flushed with fresh water after completion and the remaining time is an empty tube. Due to incomplete cleaning, the residual cement slurry on the inner surface of the measuring tube solidified into a thin layer, which accumulated in the past two months to form an insulating layer, covering the entire surface of the electrode, resulting in abnormal operation and eventually failing to work.
The other is on the electrolytic cutting process test device. The flow of saturated saline solution is controlled by an electromagnetic flowmeter. After a period of gaps, the flow signal is gradually reduced, and the signal is zero after 2 months. The reason is that iron oxide deposits the wall of the pipe during electrolytic cutting and causes a short circuit. Clear stratification immediately returns to normal.
Second, the electromagnetic flowmeter maintenance regularly check the sensor electrical performance
First, the inter-electrode resistance was roughly measured. Disconnect the signal between the sensor and the transducer. The sensor is filled with liquid. Use a multimeter to measure the resistance of the two electrodes and the ground. Whether it is within the specified range of the manufacturer and the measured values ​​are approximately the same. Recording first measured resistance value, and this value is determined after the sensor failure reasons (e.g., the deposited layer is electrically conductive or insulating) are useful.
Next, the sensor is vented to the liquid, the inner wall is wiped clean, and the resistance between the two electrodes and the grounding terminal is measured with a megohmmeter after it is completely dry.
Finally, check the insulation resistance of the excitation coil, remove the sensor excitation coil, connect the terminal to the converter, and use a megohmmeter to measure the insulation resistance of the coil.