There are two types of failures in the operation of the electromagnetic flow meter. One is caused by the damage of instrument structure or components. The other is the failure caused by external reasons, such as improper installation, movement distortion, deposition and scaling. This article will discuss these two types of failures.
1. Cause analysis
This type of failure is more common during the use process, and the reasons are generally as follows:
(1) The power supply of the meter is abnormal.
(2) The cable connection is abnormal.
(3) The liquid activity condition does not meet the installation requirements.
(4) Components of the electromagnetic flow meter sensor are damaged or a layer is attached to the inner wall of the flow meter.
(5) The converter components are damaged.
It is needed to confirm that the power has been connected, and check whether the output voltage of the power circuit board is normal. The whole power circuit board can be replaced to check whether it is good or bad.
It is needed to check whether the cables are in good condition and correctly connected.
It is needed to check the direction of liquid movement and whether the tube is full of liquid. For the positive and negative measurement of the electromagnetic flow meter, it can be measured if the direction is inconsistent. However, it should be corrected if the direction of the set display flow is inconsistent. If the workload of disassembling the sensor is heavy, you can also change the direction of the arrow on the sensor and reset the display instrument symbol. The lack of liquid in the pipe is mainly caused by the improper installation position of the sensor. Therefore, measures should be taken during installation to avoid causing insufficient liquid in the pipe.
It is necessary to check whether the electromagnetic flow meter's electrode on the inner wall of the transmitter is covered with a liquid scarring layer. For the measuring liquid that is easily scarred, it should be cleaned up regularly.
The converter components should be replaced if the fault is caused by their damage.
1. Cause analysis
This type of fault is caused by the measurement medium or the influence of the external environment, and the fault can be eliminated by itself after the external interference is eliminated. This type of fault can not be ignored to ensure the accuracy of the measurement. In some production environments, the increase of the measuring pipe or liquid of the electromagnetic flow meter will cause the circuit board of the electromagnetic flow meter to loosen, and it can also cause the fluctuation of the output value.
It is needed to confirm whether it is the cause of process manipulation. When the fluid pulsates, the electromagnetic flow meter only truthfully reflects the activity status, and the fault can be eliminated by itself after the pulsation.
External stray currents can cause electromagnetic interference. It is necessary to check whether large electrical appliances or electric welding machines are working in the operating environment of the instrument. Also, it is necessary to make sure that the instrument is grounded and the operating environment is good.
When the pipe of the electromagnetic flow meter is not full of liquid or the liquid contains bubbles, both are caused by technological reasons. At this time, the process personnel should be asked to confirm that the output value can be restored to normal after the liquid is full or the bubbles are flattened.
The transmitter circuit board has a plug-in structure. The power plate of the flow meter is often loosened due to the increase of measuring pipe or liquid. If it happens, the electromagnetic flow meter can be removed and the circuit board should be fixed again.