NATA News Archive
- Published: 24 September 2014
NATA’s policy with regards to metrological traceability applicable to all facilities accredited by NATA has undergone a significant revision as a result of changes made to the International Laboratory Accreditation Cooperation’s (ILAC) policy on traceability of measurement results, ILAC P10. In the revision of their policy for metrological traceability ILAC has recognised that metrological traceability of measurement results is a key topic for which a harmonised international policy is needed if the market is to have confidence in calibrations, testing and inspections performed by accredited laboratories and inspection bodies.
Metrological traceability requires an unbroken chain of calibrations to stated references, all having stated uncertainties. The persistent misconception that metrological traceability may be linked to a particular organization (e.g., “traceable to a specific National Metrology Institute”) fosters continued confusion with regard to its nature. Metrological traceability pertains to reference quantity values of measurement standards and results, not the organisation providing the results.
In essence the fundamental requirements for metrological traceability in accreditation have not changed. The revision of ILAC’s policy on traceability and NATA’s corresponding policy provides additional guidance as to the detail and content of records maintained and of the verifications conducted by our facilities in demonstrating traceability to applicable national measurement standards. Following the criteria set in the standards for which NATA accredits, ISO/IEC 17025 and 15189, the updates in Policy Circular 11 addresses the grey areas where calibrations are conducted internally, by non accredited service providers or where calibrations can not be strictly made to SI units. When determining that an instrument is not critical to the outcome of a test, the accredited facility must maintain records demonstrating that the instrument is not a dominate factor to the quality of the test result. Reference materials and standards which have no clear evidence of measurement traceability and not issued with an endorsed certificate are to be considered as critical consumables and facilities are to maintain records that demonstrate they are suitable for their intended use and complying with the specified requirements for which these materials are used.
Policy Circular 11 applies to all measurements, physical, chemical or biological, however it is acknowledged that the concept of metrology traceability of measurement results in fields such as the chemical, medical, and biological sciences is still under development.
This revision of NATA Policy Circular 11 assists NATA in continuing to meet our mutual recognition commitments under the ILAC MRA.
For any further questions on the application of Policy Circular 11 please contact your NATA client coordinator.