ISO/IEC 17025 calibration explained

ISO/IEC 17025 is the international standard for the competence of testing and calibration laboratories. An accredited calibration is one performed within a laboratory's accredited scope, under a management system assessed by a national accreditation body (for example UKAS in the United Kingdom).

What the standard asks for

• Impartiality and confidentiality.
• Competent personnel with defined responsibilities.
• Suitable facilities and environmental conditions.
• Equipment that is calibrated, maintained and controlled, with records.
• Metrological traceability of results to the SI or to agreed references.
• Validated methods, and evaluation of measurement uncertainty.
• Technical records, reporting requirements for certificates, and control of nonconforming work.
• A management system with internal audits and corrective actions.

What an accredited certificate gives you

Traceable results with a stated uncertainty, produced under an assessed system. Where the certificate includes a statement of conformity, the decision rule applied must be stated. The accreditation symbol on the certificate is what distinguishes an accredited calibration from a non-accredited one performed by the same laboratory.

What it does not give you

Accreditation does not mean the instrument is fit for your purpose, that the calibration interval is right, or that the reported uncertainty is small enough for your application. Those are the customer's decisions. ValiTrac is designed around these workflow elements — traceability, uncertainty, technical review, records — but is not itself an accredited laboratory and makes no compliance claim on your behalf.