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Description of the method of properly grounding the electromagnetic flowmeter

In order to prevent the electromagnetic flowmeter from being disturbed by external parasitic potential, the sensor should have a good separate grounding wire and grounding resistance. The grounding method should be carefully implemented according to the manufacturer's information or the technical personnel's guidance. The conventional connection method is:

(1) When the electromagnetic flowmeter is installed on the grounded metal pipe, the system potential balance is realized by the grounding terminal on the electromagnetic flowmeter transmitter, that is, the copper core wire with a cross-sectional area of not less than 6 mm2 is connected to the grounding terminal.

(2) When the electromagnetic flowmeter is installed on an ungrounded metal pipe, both flanges are connected to the pipe flange through a copper core wire with a cross-sectional area of not less than 6 mm2, and grounded; the transmitter or sensor junction box Connect to the ground terminal to achieve system potential balance.

(3) When the electromagnetic flowmeter is installed on a plastic pipe or a pipe with an insulating lining, the system potential balance is achieved by an additional grounding ring. The grounding ring is connected to the grounding terminal through a copper core wire having a sectional area of not less than 6 mm2.

Does the electromagnetic flowmeter grounding ring have a grounding ring? What happens if there is no grounding ring?

The grounding ring directly contacts the medium through the grounding electrode, and then grounds through the grounding ring and the instrument flange to reach the ground potential to eliminate interference.

Grounding ring

It is often not suitable to add a grounding ring in some occasions. For example, when measuring strong corrosive media, the pipe will be made of PVC or PTFE-plated electrodes, which is precious metal. Especially for large diameter, it is impossible to match. The grounding ring is too high. In this case, three electrodes are generally selected, two of which are for measurement and the other for grounding.

Generally, if the pipe is made of metal or not with a grounding ring, the flange of the flowmeter and the pipe are connected and then grounded, which can also be used well, especially in the case of large diameter. If you have a small diameter, it doesn't matter if you have a grounding ring, and the cost will not be too much. In addition, some users do not measure strong corrosive media, but the pipeline is non-metallic. At this time, it must be equipped with a grounding ring. Grounding is very important for electromagnetics. The interference of the field magnetic field is fatal to the electromagnetic, because the electric field can be shielded by some means, but the magnetic field can't be shielded.

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