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When an electromagnetic flowmeter is not in use due to shutdown, it is necessary to employ scientific and appropriate methods for its maintenance. Many people find that after purchasing an electromagnetic flowmeter and using it for a while, the measurement data becomes inaccurate when it is used again. In fact, this is not a quality issue inherent in the electromagnetic flowmeter itself. It is because the user did not carry out maintenance and care according to the methods outlined in the manual. I. Zero-point inspection and adjustment for the maintenance of electromagnetic flowmeters Before putting an electromagnetic flowmeter into operation, it is necessary to adjust the zero point while the electromagnetic flow sensor is filled with liquid and at rest, after powering it on. After coming online, it is also necessary to periodically shut off the flow under operating conditions for zero-point checks ； Especially for precipitated or easily contaminated electrodes, as well as non-cleaning fluids containing solids, more inspections should be carried out during the initial operation phase in order to gain experience and determine an appropriate inspection schedule. Electromagnetic flowmeters with AC excitation are more prone to zero drift compared to those with rectangular wave excitation; therefore, extra attention should be paid to their inspection and adjustment. Give two examples of application failures caused by faults in sedimentary layers. In oil drilling cementing operations, the total flow rate of the cement slurry is an important process parameter, and high-pressure electromagnetic flowmeters are often used for measuring it. The instrument is used intermittently; after use, the sensor measurement tube is rinsed with clean water, and it remains empty for the rest of the time. Due to inadequate cleaning, cement slurry remaining on the inner wall of the measurement tube hardened into a thin layer; over the course of nearly two months, this layer accumulated to form an insulating layer that covered the entire surface of the electrode, resulting in abnormal operation of the electromagnetic flowmeter and ultimately its inability to function. In the other case, on the electrolytic cutting process testing device, an electromagnetic flow meter was used to control the flow rate of saturated saline; after being in use for a period of time, the flow rate signal gradually weakened, and after 2 months the signal became zero. The reason is that iron oxide deposits on the tube wall during electrolytic cutting, causing a short circuit. Removing the buildup restores normal conditions immediately. II. Regular inspection of the electrical properties of the sensor in the maintenance of electromagnetic flowmeters First, roughly measure the resistance between the electrodes. Disconnect the signal connection between the sensor and the converter; fill the sensor with liquid, and use a multimeter to measure the resistance values between the two electrodes and the ground terminal. Check whether these values fall within the range specified by the manufacturer, and ensure that the two measured values are roughly equal. Record the resistance value measured for the first time; this value is useful for later determining the cause of sensor failures (such as whether the deposition layer is conductive or insulating). Next, drain the liquid from the sensor, wipe clean the inner walls, and after they are completely dry, use a megohmmeter to measure the resistance between the two electrodes and the grounding terminal. Finally, check the insulation resistance of the excitation coil of the electromagnetic flowmeter: remove the excitation coil from the sensor, connect the terminals to the converter with wires, and use a megohmmeter to measure the insulation resistance of the coil. For more information, please visit the company’s official website at http://www.yb1518.com/. Please retain this link when reproducing the content! http://www.yb1518.com/UploadFiles/2012717174126829.jpg