Inter-laboratory Comparisons and Their Roles in Accreditation

Abstract

Results of interlaboratory comparisons and proficiency tests are a significant parameter for the calibration and testing laboratories for assuring the quality of test and calibration results performed by those laboratories. If test and calibration laboratories want to demonstrate that they operate according to a management system, that they are technically competent and that they can produce technically valid results in the tests and calibrations they perform for their customers, the general requirements they must meet are defined in ISO/IEC 17025:2017. This international standard forms the basis of international laboratory accreditation. Clause 7.7 Ensuring the validity of results in this standard requires laboratories to establish the procedures and instructions and other technical documentation needed to ensure the results of the tests and calibrations they perform. Participation in inter-laboratory comparison or proficiency testing programs is one of the most important of these activities. Participation in inter-laboratory comparisons provides an opportunity for laboratories to independently evaluate their analytical performance, both in absolute terms and in comparison, to other techniques. In this study, information about calibration laboratories and accreditation activities is given and the importance of inter-laboratory comparison studies is explained to ensure the results of the measurements made by calibration laboratories.