ISO/IEC 17025 Clause 6.5.3 addresses the situations where direct traceability to SI units isn’t technically feasible. In such cases, labs must ensure measurement traceability to an alternative, recognized reference which are following:
Certified Reference Materials (CRMs) from Competent Producers:
The lab can use CRMs that are
certified by accredited Reference Material Producers, ensuring reliability and
consistency. These CRM come with certified values, offering traceability and
credibility for measurements even when SI unit traceability is not achievable.
· Example: For pesticide residue analysis, where direct SI traceability might not be feasible for certain pesticides, a food testing lab can use a Certified Reference Material (CRM) containing a known concentration of the specific pesticide. This CRM, obtained from an ISO 17034-certified producer, provides a certified value for the pesticide concentration. By using this CRM, the lab ensures metrological traceability for its measurement process, even though direct SI traceability isn't achievable. This approach maintains accuracy and reliability in detecting and quantifying pesticide residues in food products.
. Reference Measurement Procedures, Consensus Standards
Labs can use well-established methods or consensus standards as an alternative for traceability. These are validated methods, widely accepted in the field, and deemed suitable through inter-laboratory comparisons or studies.
Example: In food safety testing, where direct SI traceability for certain allergens may not be possible, the lab could use a validated ELISA method or a standard protocol that has been widely accepted and verified for its intended application.
No comments:
Post a Comment