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Electromagnetic flowmeter fault check and solution

Electromagnetic flowmeter troubleshooting and adoption methods 1, the activity itself shakes (or pulsation) View the first item of the flow chart. If the activity itself is shaken, the appearance of the output sway is a true reflection of the shake. View methods can be used to ask operators or process technicians at the application site to see if there is any source of shaking. The reasons for the shaking (or pulsation) of the pipe system are generally threefold: (1) The active power source upstream of the electromagnetic flowmeter uses a reciprocating pump or a diaphragm pump (often used for fine chemicals, food, medicine, and water purification). Injection liquid), the pumping frequency of these pumps is generally back to more than 100 times per minute; (2) improper control of the flow characteristics and size of the control valve, and then hunting, which can be investigated and controlled Whether the valve stem has vibratory movement; (3) Other disturbance sources cause the activity to shake, for example: whether there is a vortex in the upstream pipe of the electromagnetic flowmeter (such as a full-open butterfly valve) (such as a vortex flowmeter vortex body) The vortex of the attack, the gasket at the inlet end of the sensor extends into the flow passage, the flaky fragments of the gasket hang in the liquid flow, and the like. In pipelines with pulsating active sources, to reduce the impact on the flow measurement, generally use the flow sensor away from the pulsation source, use the flow resistance to attenuate the pulsation; or install a gas chamber called a passive filter in the appropriate orientation of the pipeline. Buffer, absorbing pulsation. 2. The pipe is not filled with liquid or contains bubbles in the liquid. See the second item of the flow chart. This type of fault is mainly caused by poor design of the pipe network, which makes the measuring tube of the sensor not overflowing with liquid or improper installation of the sensor. The method should be adopted to avoid the installation of a, e-direction as shown in Figure 3 and the b-direction when discharging with a dotted line, and to the c, d orientation. There is no back pressure or back pressure in the sensor. If it is installed in the azimuth e, the liquid flows through the pipe for a short period of time. It is discharged into the atmosphere. If the valve 2 is fully open, the sensor may not be filled with liquid in the measuring tube. Sometimes the flow of the process is large enough to overflow and the appearance of the flow is normal. If the flow is reduced, the liquid may be dissatisfied and the appearance may be abnormal. The gas contained in the liquid The bubble gas in the liquid constitutes two ways of inhaling from the outside and converting the dissolved gas (air) into a free bubble in the liquid. The number of bubbles in the liquid is small and the diameter of the bubble is much smaller than the diameter of the electrode. Although the volume of the liquid is reduced, the output of the electromagnetic flow juice is not shaken; the larger bubble can conceal the entire electrode by rubbing the electrode, so that the flow signal loop When the circuit is opened instantaneously, the output signal is shaken even more.

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