Components of a Calibration Certificate

Certificate of Compliance

The National Conference of Standards Labs International (NCSLI) Publication, "Recommended Standard Operating Procedure for Preparation of Calibration Certificates" (SOP 1) also refers to a certificate of compliance/noncompliance:

2.15. Where relevant, a statement of compliance/non-compliance with requirements and/or specifications. Compliance refers to all criteria of a referenced standard and not just a portion (e.g., compliance to all specifications and tolerances versus tolerance only). When all criteria have not been assessed, the laboratory must identify which criteria have/have-not been evaluated.

The certificate of calibration specifies information about observed measurement tolerances compared to a known standard under given conditions, but the instrument being calibrated may have other specifications in addition to the stated tolerances that are not reflected on a certificate of calibration. Examples would include a range of line voltage inputs for an electronic device, a range of temperature for "in-tolerance" conditions, or a temperature range for "operational conditions". Specifications may also exist for the appearance or surface finish of a device. A manufacturer normally certifies to a customer that all the specifications are being met by issuing a certificate of conformance.

Some customers may request this certificate in addition to a certificate of calibration. A COC alone does not guarantee that the instrument has been calibrated to national or international standards.