在停机即不使用的时候，我们要对电磁流量计采取科学合理的维护和保养方法。 When the electromagnetic flowmeter is not used when it is stopped, we must adopt scientific and reasonable maintenance and maintenance methods for the electromagnetic flowmeter. In providing electromagnetic flowmeter technical services to users, users often encounter inaccurate measurement data after purchasing the electromagnetic flowmeter for a period of use. In fact, this is not a quality problem of the electromagnetic flow meter itself. Because the user does not follow the post-use care and maintenance methods in the manual.
维护之零点检查和调整：电磁流量计投入运行前，通电后必须在电磁流量传感器充满液体静止状态下调整零点。 I. Zero point inspection and adjustment of electromagnetic flowmeter maintenance: Before the electromagnetic flowmeter is put into operation, the zero point must be adjusted after the electromagnetic flow sensor is full of liquid after the power is turned on. After being put into operation, it is necessary to periodically check the zero point according to the conditions of use. Especially for precipitates and easily polluted electrodes, non-cleaning liquids containing solid phases should be checked at the beginning of operation to obtain experience to determine the normal inspection cycle. The AC magnetic field flowmeter and rectangular wave excitation ratio are more likely to produce zero drift, so more attention should be paid to inspection and adjustment. Take two examples of application errors where the deposits have failed. One is that in the oil drilling and cementing project, the total flow of cement slurry is an important process parameter, and high pressure electromagnetic flow meters are often used. Use the meter intermittently. Rinse the sensor measuring tube with clean water after use. The remaining time is empty. Due to incomplete cleaning, the residual cement slurry on the inner wall of the measuring tube has solidified into a thin layer, which has accumulated in the past two months to form an insulating layer, covering the entire electrode surface, resulting in abnormal operation and eventually failure to work. The other is an electrolytic cutting process inspection device, which uses an electromagnetic flowmeter to control the flow of saturated saline solution. After a period of use, the flow signal is gradually weakened, and the signal is zero after 2 months. The reason is that iron oxide deposits on the tube wall during electrolytic cutting, resulting in a short circuit. Clear the layer to return to normal immediately. 2. Periodically check the electrical performance of the sensor for electromagnetic flowmeter maintenance: First, roughly measure the resistance between the electrodes. Disconnect the signal connection between the sensor and the converter, the sensor is filled with liquid, and use a multimeter to measure the resistance value of the two electrodes and the ground terminal, whether it is within the range specified by the manufacturer, and the measured two values are substantially the same. Record the resistance value measured for the first time. This value is useful for later determining the cause of the sensor failure (such as whether the deposited layer is conductive or insulating). Secondly, drain the sensor from the liquid and wipe the inner wall. After it is completely dry, use a megohmmeter to measure the resistance between the two electrodes and the ground terminal. Finally, check the insulation resistance of the exciting coil, remove the sensor exciting coil, wire the terminal indirectly to the converter, and measure the insulation resistance of the coil with a megohmmeter.
的电源和信号需要四根电缆。 The power and signals of a conventional electromagnetic flowmeter require four cables. But two-wire meters that can reduce cable costs and simplify installation are becoming more common in grassroots plants using fieldbuses. Although the two-wire electromagnetic flowmeter will grow during this forecast period, the main body of sales will still be four-wire products for direct replacement. Due to strict environmental protection requirements, some process industries, especially chemical, paper and water treatment, are all under the strict supervision of authoritative organizations. This will drive an increase in the production of electromagnetic flow meters. In addition, the privatization of municipal water treatment has become an international trend, which will generate new investments to renew aging water treatment and sewer systems. Multi-variable electromagnetic flow meters capable of measuring temperature and pressure in addition to flow measurement have also been put into commercial use. Although its production was insignificant in 2002, growth can be expected throughout the forecast period. This enhanced measurement capability allows users to reduce the number of instruments purchased and require fewer process measurement points, thereby reducing potential leak paths. At the same time, electromagnetic flowmeters suitable for non-full-pipe flow measurement, reinforced electrodes with improved signal-to-noise ratio, and non-contact electrodes are also examples of product innovation. They will attract users' interest in electromagnetic flowmeter technology.