The Turkish Accreditation Agency (TรRKAK) has comprehensively updated R20.02 Guidelines for the Estimation of Measurement Uncertainty in Test/Analysis Results, which is of vital importance for accredited testing and analysis laboratories, with Revision 02 as of 02.10.2025. This revision aims to reinforce laboratories’ compliance with international standards and best metrological practices.
Among the main innovations of the update is the full alignment of the policy on measurement uncertainty estimation with practice, based on the GUM approach for calibration and physical fields and the EURACHEM/CITAC approach for other areas of analysis. The scope of the guidance has also been clarified, detailing the requirements for measurement uncertainty assessment for tests whose final outcome is qualitative (pass/fail) but which rely on quantitative measurement.
The most critical changes in the Guidance are the detailed guidance on the reporting of measurement uncertainty for full compliance with TS EN ISO/IEC 17025:2017. In particular, Revision 02 makes it an explicit requirement to report uncertainty where the test result is close to or likely to exceed the tolerance limit, even if a declaration of conformity is not submitted. This step is mandatory for clients to interpret the results, apply the decision rule and make a risk assessment.
Laboratories are expected to quickly update their processes according to these new requirements. The current guide is available on TURKAK’s official website.
