Brief electromagnetic flowmeter how to zero point adjustment

　　After power on, the zero point must be adjusted when the electromagnetic flow sensor is full of liquid and stopped. After it is put into operation, the flow should be stopped regularly for zero point inspection according to the application conditions; especially for accumulation, easy to contaminate electrodes, and non-clean liquids rich in solid phases, more inspections should be carried out in the early stage of operation to obtain experience to determine the normal inspection cycle.

　　Compared with the rectangular wave excitation, the electromagnetic flowmeter with AC excitation is more prone to zero drift, so it is more important to check and adjust it. The total flow of the cement slurry is the main technical parameter. Here are two examples of misuse of the deposition layer. One is in the oil drilling cementing project. High-pressure electromagnetic flowmeters are often used. The surface is used intermittently, and the sensor measuring tube is rinsed with clean water after use. The tube is empty at other times. Due to incomplete cleaning, the residual cement slurry on the inner wall of the measuring tube solidifies into a thin layer. In the past two months, it has accumulated to form an insulating layer, covering the entire electrode surface, resulting in abnormal operation and ultimately failure to work.

　　The flow rate of saturated salt water was controlled by an electromagnetic flowmeter, and the other was on an electrolytic cutting technology test device. After a period of use, the flow signal was gradually weakened, and the signal was zero after 2 months. The reason was that iron oxide accumulated on the pipe wall during electrolytic cutting, forming a short circuit. Removing the accumulation immediately restored the system to normal.