Evaluation of Measurement Uncertainty for Testing & Calibration laboratories as per ISO/ IEC 17025:2017 standard requirements

Abstract

Measurement uncertainty is a qualitative measure of measurand in addition to precision and accuracy. Estimation of uncertainty in measurement is one of the most important characteristics for demonstration of competence for testing and calibration laboratories accredited on ISO/ IEC 17025 standards. To ensure the metrological traceability, to have confidence in measurements and to produce valid results, laboratory must estimate uncertainty from all significant sources. Consequently, measurement uncertainty can have impact on decision rules, statement of conformity and risk associated while making decisions with reference to a standard or specification. This paper presents a concise guideline for estimation of measurement uncertainty for testing and calibration laboratories with focus on electrical whether accredited on ISO/ IEC 17025:2017 standards or planned to be achieve accreditation in future. Non-accredited electrical testing and calibration laboratories may adopt the procedure/ process to enhance acceptability, to ensure confidence in measurement results and as a part of good laboratory practices. Finally, authors presented their way of budgeting measurement uncertainty as an example which is being implemented in electrical testing laboratory.