| Abstract: |
This paper discusses the distinction between measurement uncertainty, measurement errors and their role in the calibration process. The issue of including uncorrected bias is addressed and a method to extend the current ISO Guide to the Expression of Uncertainty in Measurement to include the case of known, but uncorrected, measurement bias is presented. Although it is strongly recommended that measurement results be corrected for bias, in some situations this may not be practical, hence an extension to the Guide is proposed to address this special situation. The procedure involves modifying the calculation of the expanded uncertainty, allowing it to become asymmetric about the measurement value. The method is compared to other alternative procedures, and an illustration of how it affects tolerance zones is presented. |
