Calibration Standards

Standards are codified requirements for a process such as calibration or compliance. Promulgated by cooperative industry bodies and/or governmental entities, standards are the cornerstone of calibration.

Three key industry standards govern the way calibration is done around the world today:

• ISO/IEC/EN 17025 (compliant): the most rigorous globally-accepted standard. Prescribes "General Requirements for the Competence of Calibration and Testing Laboratories". The service organization providing this calibration meets the requirements of ISO17025.
• ISO/IEC/EN 17025 (accredited): the most rigorous globally-accepted standard. Prescribes "General Requirements for the Competence of Calibration and Testing Laboratories". This is verified by an independent accrediting body operating under ISO17011.
• ANSI/NCSL Z540-1-1994 (R2002): known as "Z540". A U.S. standard that sets compliance guidelines for "Calibration Laboratories and Measuring and Test Equipment".
• ISO 9001: a set of quality management process standards that confirms adherence to quality guidelines, including calibration and maintenance.

Every compliant calibration will be accompanied by a calibration certificate and other documentation attesting to the standards that have been followed.

A compliant calibration means confidence in the results. Sometimes a freshly "calibrated" instrument comes back to its owner out of specification or with incomplete documentation about traceability and procedures. This may imply that the instrument was calibrated with non-compliant tools or procedures.

Proper calibration means compliance with standards, including traceability requirements, documentation, processes, and competencies. Without this compliance, the calibration—and its measurement results—may be invalid.

Standards Facts

• Specific industries, local regulations, or your customers may require 17025-compliant calibration on your test equipment.
• Local governmental regulations may add requirements beyond calibration standards.
• Calibration in an ISO 9001-compliant facility does not guarantee accreditation.