How to solve the fluctuations in Yokogawa’s electromagnetic flowmeters
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Dear teachers, two Yokogawa electromagnetic flowmeters are installed on one pipeline; one provides stable measurements while the other shows fluctuations from time to time. Question: What parameters should be adjusted to stabilize the readings of the meter that experiences fluctuations?
It’s possible that there are fluctuations in the medium inside the actual pipeline
Why are 2 units installed on one pipeline? There must be a distance of at least 10D in between.
It would be best to send some pictures of the installation site; this will help everyone analyze the cause for you.
The fluctuation in your case is very small: the deviation is 0.1 cubic units, with fluctuations of around 0.02 cubic units. Are you really sure it’s necessary to worry about this? If it is indeed necessary, first check whether the flow meters experiencing fluctuations are properly grounded and whether grounding rings are installed. Then close the upstream and downstream valves, zero both flow meters while the pipes are full, increase the damping time by 0.5 seconds, and adjust the filtering time in the DCS to 1 second or 2 seconds.
I fully agree with your view. Yokogawa’s electromagnetic flowmeters generally use a dual-frequency excitation method, making them the most stable type of electromagnetic flowmeter. This fluctuation on the DCS is likely due to issues with the pipeline or installation; it has nothing to do with the quality of the electromagnetic flowmeter itself.
It may seem small, but this fluctuation can be as much as 5 m3; sometimes it exceeds 10 m3, and it can reach the interlock value