It Is Time for Measuring Instruments to Report Measurement Uncertainty

Abstract

When reporting the result of a measurement, the Guide to the Expression of Uncertainty in Measurement (GUM) makes it clear that a complete result includes a measured value and an associated value of uncertainty. Measuring instruments compute and then indicate a measured value, but many, if not most instruments provide no indication of the measurement uncertainty. This leaves the metrologist to compute the uncertainty, incurring two parallel computation paths. One path is through the measuring instrument, the other managed by the metrologist. It is feasible to merge these two paths where the instrument computes the uncertainty. This positively impacts the metrologist’s workflow. This article takes a previously reported measurement as a use case and compares the metrologist’s workflow when using measuring instruments that report measurement uncertainty and using instruments that do not. The comparison shows that using instruments that report measurement uncertainty significantly improves metrologist efficiency, leads to better estimates of uncertainty and, facilitates enhanced methods of managing and monitoring measurement processes.

Notes

1 The power meter errors do not appear directly in Eq. (1). The power meter errors are contributors to the errors associated with the $e^{01}$ term.

2 An automated procedure that reports uncertainty from Eq. (1) is feasible. However, given the complexity, and the additional data required, the implemented automated procedure for the original use case omits this feature.