What is the role of the earth ring of the electromagnetic flowmeter?
The grounding ring is directly contacted with the medium through the grounding electrode, and then grounded with the instrument flange through the ground ring to achieve ground equipotential, so as to eliminate interference.
Often in some occasions it is not suitable with the grounding ring, for example, when measuring the strong corrosive medium, selective electrode often use PVC or PTFE lined pipe is the precious metals, especially for large diameter, it would not be possible with the grounding ring, the cost is too high. In this case, three electrodes are generally selected, of which two electrodes are used for measurement and the other is grounded.
In general, if the pipe is made of metal material, it can also be not suitable for the ground ring. It will connect the flange and the pipe of the flowmeter and then connect it to the ground. It can also be used well, especially in the case of large caliber. If the small bore, with the ground ring does not matter, the cost will not be much worse. In addition, some users do not test the strong corrosive media, but the pipe is non-metallic, then it is necessary to match the ground ring, grounding is very important for electromagnetic. The magnetic field interference is fatal for electromagnetic, because we can take some measures for electric field shielding, but we have no way of magnetic field shielding, electromagnetic flowmeter installed so we must avoid the strong magnetic field.
