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How to check a Magflow meter?

How to check a Magflow meter?

How to check a Magflow meter?

(OP)
I have a magflow meter which seem to have stopped working. It is giving spurious reading even when nothing is passing through it. I have removed it and not found any kind of coating or damage to the internal wall. We have ordered a replacement, however I am not sure if there is anything else I can check to be sure it is in some way damaged. It has been installed without issue for more than 10 years as far as I know.

I just wondered if there is anything I can check? I understand that there is an exciter and a measure circuit. Is there anything I can measure in terms of resistance?

I do not know the manufacturer as there is 10 years of pain covering everything.

Thanks.

RE: How to check a Magflow meter?


Most magmeter vendors publish service data that includes coil resistance. Checking for coil short to ground is typical. Most also have a troubleshooting chart. But it helps to have the right manual.

Strange, impossible flow readings are actually normal in an empty magmeter. I had a 1" (25mm) tube powered up on the bench today and it showed 13-14 lpm flow rate with no liquid in the tube. It's fully functional. Works normally when the tube is full.


RE: How to check a Magflow meter?

(OP)
Thanks for that. It is reading wrong when in service as well as when empty. I am away from work at the minute but will try to find some data for it when I get back.

RE: How to check a Magflow meter?

danw2,
That is an odd reading for an empty tube. I almost always see some number that indicates all registers are full (something around 64k of whatever units it is calibrated to display) when a mag meter is partially full or fully empty. A number in the realm of reality is really quite scary.

David Simpson, PE
MuleShoe Engineering

Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat

RE: How to check a Magflow meter?

David,

I agree. Siemens Mag 5000.

RE: How to check a Magflow meter?

You can also measure the electrodes to make sure they are not grounded, should read infinity if the tube is empty. I have seen where just one grounded and the reading dropped to ~ 1/2

RE: How to check a Magflow meter?

Why would I care what a flow meter is reading when it is empty?
Unless the electronics has some version of empty pipe detection that would lock it to 4MA at a preset level, the tube output will jump all over the place when empty. Seems normal to me??

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