Evaluation of the calibration history of a measurement standard

摘要

In order to maintain traceability, a measurement standard has to be recalibrated regularly as a function of time. The data available from these recalibrations is called the calibration history of the measurement standard and includes the date and the result of each calibration together with a specification of the measurement uncertainty. This report describes how the principle of least squares can be applied in order to evaluate the drift and random changes in the value of the standard from the calibration history.