External calibration provider does not issue uncertainty of measurement

[celestica]

Our external calibration provider does not issue uncertainty of measurement. We availed of their services because our customers also use this laboratory for their calibration.

Uncertainty of measurement is now an issue because we are preparing for TS16949 certification. But it is difficult for us to look for another provider because of capability and price.

There was a suggestion that we will be the one to compute the uncertainty, and we just get data from them. Is this acceptable?

[corollax]

Unfortunately measurement uncertainty is not as straight-forward as manipulating a set of data. If for some reason the service provider cannot provide MU, I doubt they can provide the essential data for you to DIY...

[Hershal]

Corollax is correct, in that you need the external calibration provider to provide the uncertainty.

I do not know if the Phillipines accepts the 4:1 Test Accuracy Ratio (TAR) such as the U.S. has, but if so, then you do have an alternative available. For the 4:1 calculation, you take the accuracy of the instrument at your reading, and 25% of that accuracy becomes your assumed uncertainty. For example, if you have a DMM that is accurate to 100mV at a reading of 5 volts, then the assumed uncertainty becomes 25mV.

Hope this helps.

Hershal