Uncertainties

“A measurement result is only complete if it is accompanied by a statement of the uncertainty in the measurement.”  That’s quoted from Measurement Good Practice Guide No. 11 (Issue 2), A Beginner’s Guide to Uncertainty of Measurement, published by NPL.  “ISO/IEC 17025 requires calibration laboratories to report, in the calibration certificate, the uncertainty of measurement . . .”  That’s taken out of ILAC-P14:12/2010.

There are lots of guides and technical papers out there that describe how uncertainties should be calculated.  Uncertainty analyses, like calibrations, can be extremely complex or fairly simple.  Most guides say that the uncertainty analysis should be commensurate with the calibration.  That means that for most typical industrial type calibrations, the uncertainty analysis is going to be fairly straight forward.  Here’s the problem:  very few calibration labs actually report uncertainties . . . unless you want to pay through the nose.

We decided to make uncertainty reporting for our calibrations standard.  Yes, there are those calibrations for which they will not be reported:  pass/fail calibrations, for instance.  But, the vast majority of calibrations that we perform have the uncertainty reported right there on the report of calibration in the units that the measurement is reported in.

Simple . . . Different . . . Better