Magmeter Accuracy?

[jbr549]

Is there any method short of taking out the Tube and sending back to a flow lab or verifying or checking accuracy of installed unit? Anyone have a way of doing a local "bucket test?" that is acceptable??

 

[khan101]

You can put another certified calibrated meter in series with this meter and verify the accuracy.

 

[quark]

The actual calibration is always done by filling a receiver. Perhaps, the meter manufacturers can guide you about the minimum quantity (or maximum time) for this exercise.

Otherwise, go with Khan's suggestion. I will prefer a Corriolis Meter.

Regards,

 

[jbr549]

quark...I had considered your solution, but it also could pose the same question? How do I know the coriolis is accurate. How do I verify it? I guess my problem is verifying inline flow measurements without the expense of having alternative or additional inline measurements, which I also have to check then periodically???

 

[khan101]

It all depends how far you want to go. Usually when you buy a turbine or coriolis meter you get a NIST certification with your purchase which tells you the accuracy of the instrument. Using that certified instrument in series with your magmeter will determine the accuracy of the magmeter.

 

[hacksaw]

what is your accuracy requirement and what is its basis?

 

[DJCherre]

We have two coriolis meters on either end of a pipeline and they are always different by 0.2% of full scale (one always higher). Very consistent. We also have a total flow coriolis on a header serving five coriolis-measured lines. If you add up the five you get the reading of the total flow within 0.5%. They're great. We do have two others in a coating service, and flow drifts as the coating effects the meter's density measurment. From what I've seen of our ~20 coriolis meters, if they're working they're right, unless they're coated... Don't know about Mags. Our electrodes coat up and flow measurement drops...
Dean

 

[Fritzfrederix]

Hello,

Coriolis meters worked for me, We have about 40 installed. We took them in our preventive maintenance program. Every two years we flush and clean them because our product is leaving a small film on the inside of the two tubes of the coriolis. Which have effect on the measurement (accurency).
Second thing we've done is installing a pressure transmitter and connect it to the elektronics of the flowmeter because the higher the pressure the higher is the fault in accurency. See your manual.
For the rest you could send one a year back to the supplier to let it calibrate. But I don't think that's necessary.

Rudi