ISO 17025 is the international standard for calibrations. The general requirement to issue ISO 17025 certificates are:
- The company must have an ISO 9001 certified quality management system, meaning all processes must be documented.
- The laboratory as such must be mapped and accredited by local authorities (e.g. Switzerland: SAS/SCS, USA: NIST, Germany: DaaKs, UK: UKAS)
- The calibration method used, including measurement uncertainties, must be documented and accredited by the local authorities.
- Two issuing people giving their approval
- The entire process is not just GAMP5 validated but also approved by the accreditation body.
Auditors often prefer ISO 17025 to factory calibrations, since it is a known industry standard set by an official regulatory instance.