CLAS Requirements Document 9, August 2025
1. Scope
- 1.1 This document provides detailed requirements for the metrological traceability of measurements performed by accredited and applicant calibration laboratories assessed by CLAS.
- 1.2 This document conforms to the requirements of ISO/IEC 17025, General Requirements for the Competence of Testing and Calibration Laboratories, and to the International Laboratory Accreditation Cooperation (ILAC) traceability policy ILAC P10 ILAC Policy on Metrological Traceability of Measurement Results.
2. Requirements for establishing metrological traceability to the International System of Units (SI)
For all capabilities listed in the CLAS Certificate, when metrological traceability is required, calibration laboratories must establish the metrological traceability for their measuring equipment (calibration of reference standards and/or use of certified reference materials) from the sources listed in ILAC P10.
3. Requirements when metrological traceability to the International System of Units (SI) is not technically possible
When metrological traceability to the SI is not technically possible, the calibration laboratory shall demonstrate metrological traceability to an appropriate reference, as required in ILAC P10.
4. Metrological traceability sources not meeting these requirements
When metrological traceability sources do not meet either of the requirements stated in section 2 or section 3 above, these situations will be handled on a case by case basis by CLAS Technical Advisors.
CLAS Technical Advisors will use the guidelines documented in ILAC P10 to assess these sources.