Introducing a Simple Guide for the evaluation and expression of the uncertainty of NIST measurement results

The current guidelines for the evaluation and expression of the uncertainty of NIST measurement results were originally published in 1993 as NIST Technical Note 1297, which was last revised in 1994. NIST is now updating its principles and procedures for uncertainty evaluation to address current and emerging needs in measurement science that Technical Note 1297 could not have anticipated or contemplated when it was first conceived. Although progressive and forward-looking, this update is also conservative because it does not require that current practices for uncertainty evaluation be abandoned or modified where they are fit for purpose and when there is no compelling reason to do otherwise. The updated guidelines are offered as a Simple Guide intended to be deployed under the NIST policy on Measurement Quality, and are accompanied by a rich collection of examples of application drawn from many different fields of measurement science.