Setting and Using Target Uncertainty in Chemical Measurement

Contents

The Eurachem/CITAC Measurement uncertainty and traceability working group has prepared this Guide to as part of a sequence of guidelines that aims at promoting the production of measurement results that are traceable to an adequate reference and are reported with reliable and sufficiently low uncertainty for the intended use of the measurement. These features are essential for the adequate interpretation of the measurement result which is discussed in the Eurachem/CITAC guide, ‘Use of uncertainty information in compliance assessment’.

This document discusses how to set a maximum admissible uncertainty, defined in the third edition of the International Vocabulary of Metrology as the “target uncertainty”, to check whether measurement quality quantified by the measurement uncertainty is fit for the intended purpose.

Target MU 178pxThis guideline is applicable to analytical fields where the target uncertainty is not set by the regulator or the client, or where a minimum difference of the studied parameter in the same or different items must be detected in R&D work. This guide discusses how to set the target uncertainty for process development and for applied or fundamental research using information about the smallest difference or system trend that must be distinguished in a reliable way.

This guideline can also be useful for authorities and stakeholders that feel the need to define or upgrade criteria for measurements quality. The setting of target values for the so called conventional performance characteristics (precision, trueness, etc.) can miss the control of important uncertainty components included in sound uncertainty evaluations.

The document fills a gap in the current list of guidance for measurements in chemistry and can contribute to ensuring measurements play their role in the management of socio-economic interests and in the technological and scientific developments of society.

Availability

You may download the Guide from this website at no cost. 

NB: See also "Comments and errata" below.

Translations

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

Recommended citation

This publication should be cited* as: “R. Bettencourt da Silva, A. Williams (Eds), Eurachem/CITAC Guide: Setting and Using Target Uncertainty in Chemical Measurement, (1st ed. 2015). ISBN: 978-989-98723-7-0. Available from www.eurachem.org.”
*Subject to journal requirements

Approval and publication

This guide was approved for publication** by the Eurachem GA in May 2015 and first published on this website on 2015-09-28.
**Subject to minor comments

Comments and errata

Since publication of the Guide in 2015, a number of minor typographical issues have been identified. Although not sufficient to justify revision and re-issue of the complete Guide and translations, the Measurement Uncertainty and Traceability WG have prepared a list of comments and corrections for reader information. These are likely to be implemented in future editions.