Electromagnetic flowmeter grounding
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The electromagnetic flowmeter is equipped with a grounding ring; is it still necessary to ground it when installed on carbon steel pipelines? I hope experts can give some advice, thank you!
The grounding ring comes into direct contact with the dielectric through the material of the part near its inner surface; there is no separate component known as a grounding electrode. Some sensors make contact with the medium through built-in grounding electrodes. The input amplifier of an electromagnetic flowmeter usually features a differential input (except in the case of electromagnetic flowmeters with only one electrode, which is rare); in other words, the \"ground\" of the signal amplifier must be connected to the \"ground\" of the signal source. This grounding is essential for accurate measurement, as the common-mode rejection capability of differential amplifiers is limited. If the input terminals of the amplifier are not connected to the ground of the signal source and remain floating, it will cause abnormal operation of the circuit and prevent the instrument from functioning properly. Therefore, in certain situations (such as when the process pipeline is made of non-metallic material or has an insulating lining), it is necessary to use grounding rings or grounding electrodes. As for connecting to the actual ground, it is indeed necessary to resist interference. In application environments with a favorable electromagnetic environment, it may not be necessary to ground the system, as process pipelines are generally connected to the ground as well, though the grounding resistance is not ideal.
Thanks to the guy upstairs; his explanation was very detailed, I’ve learned something!
It’s better to connect it; I used to think the same way too, but I found it wasn’t ideal.
Reply to 2# syltshen: Buddy, a differential amplification circuit outputs the difference between two voltage signals applied as inputs. So, which two voltage signals does an electromagnetic flowmeter provide to the differential amplification circuit? I don’t understand; please give some guidance. Thank you! If there’s any information available, it would be helpful too; dcl2030@qq.com
I see that the electromagnetic flowmeters in our factory aren’t grounded; they’re just connected in a way that’s not proper. .
Reply to 2# syltshen: Thank you, I’ve learned it!
Reply to 6# zhuirvine: Does it only work if it’s not grounded or connected to anything?
Grounding is necessary; without it, our equipment cannot be used, and the errors are very large