Calibrated Flow Meters

My experience working at a refinery back in the day was we had to send our 8" flow meter out to be certified.

Our flow meter was fitted to the discharge side of an oil water separator. The EPA required us to get it re-certified once a year.

I went to the certification lab once and they had a pretty elaborate set up for testing and certifying. Piping and tanks so they could measure at different flow rates.

I guess this could be done in the field but I thought there was some issue about being a certified testing laboratory to actually certify a flow meter.

To answer your question, yes, you can hire an outside company but I believe you would have to send your flow meter to them for certification.

Sorry Iris, I disagree.

Firstly let us not talk about the flow stands which are not accredited according to ISO 17025.

Now about the stand (or flow calibration rigs) which have got accreditation. While getting accreditation all the factors of using different media, affects of temperature, pressure, density, buoyancy, viscosity are considered.

Besides, normally rigs are either for mass flow measurement principle, by gravimetric principles or volume flow measurement by reference volume comparison. Both methods have traceability chain.

Viscosity has no real role in flow calibration. With other factors like pressure, temperature the density changes. The density has clear effect of calibration. If we are using gravimetric method for volume flow rate calibration or volumetric method for mass flow calibration, the density is very important. But, if we are using gravimetric method for mass flow rate calibration, density doesn't come in picture. Similarly, if we are using volumetric method for volume flow rate calibration, density has no role to play.

Besides, if it is very important, there are flow stand available where actual media (oil) is used for calibration, instead of water.

Good you are satisfied with measurement in bucket, but thats not called the calibration and not at all accurate to even 5%. Here volume measurement is also not accurate and stop watch.... manual response time itself is 0.3 second. It is just mental satisfaction.

And "custody transfer" is synonymous with "cash register" so make sure everyone's on the same page when that sticker gets licked. There are lots of flow solutions out there. Here's one I've been looking into lately. (usual disclaimer).

Thank you for all of the answers. I will be contacting our customer for more details.

It depends upon many factors.

What accuracy you need?

Which country you are in? Do your customers need third party certification.

I am daily in calibration business. Please take my word, it is not so easy as collecting it in a beaker. For accuracy, it is much more invalved.

For site calibration, using precalibrated meter as reference is OK. But for real good accurate calibration, you need to take your meter to acrredited calibration laboratory.

Please let me know the country you are from, I can suggest the laboratory. Also inform the flow rage of your meter.

Once again we don't quite have enough information to provide accurate answers,

"oil" is vague, the size of the pipe would be nice to know

I used to do a weekly calibration of several turbine meters for a batch process using vegetable oil.

we filled a plastic trash can to about 30 gallons[one batch] & weighed the result [minus the can]. we were required to be within 1%...

suggesting an acceptable test requires a more complete picture of the intended use & required level of accuracy...

You could send it to an approved calibration lab. In the UK it would be an UKAS accredited lab (UKAS - United Kingdom Accreditation Service). They then carry out a calibration and provide certification. You might also look for SGS who do similar work. Hope this is of some help to you!

The easiest thing I would suggest would be to ask the customer if they would be satisfied with a certification from someone coming in with a benchmark/calibration standard and do it on site.

If not, see the other posts.

Baby steps people...LOL

Yes you can hire a contractor and no it need not be removed. Purchase of a pre-calibrated meter does not help as it will need to be calibrated at regular intervals.

Here is an extract

When seeking a calibration solution, flowmeter users have the choice of sending their meters to an outside primary standard calibration lab for service, or of employing a secondary standard portable calibration system that allows calibrations to be performed "in-situ" without removing the meter from service.

The manufacturer is supposed to certify and guarantee the accuracy (within tolerance) of their products. You can go to the manufacturer and ask for the certified factory calibration/test report, you may have to pay a bit more but no manufacturer can make and sell a flow meter with unknown operating limits, that would be absurd so they should have proper documentation.