From time to time, companies will ask for NIST Numbers to accompany their calibration reports. Often this request is driven by third party auditing services that fail to comprehend the limitations placed upon calibration laboratories by the governing bodies. This issue often leads to confusion on the part of the customer who is caught in the middle as they try to comply with the requests from an auditor who is misinformed about this issue.
For example, a NIST numbers does not confirm if the gage met tolerance, or is in within specification.
Also, a NIST number does not reference the Measurement of Uncertainty of the lab providing the the calibration.
NIST Numbers are report numbers issued by NIST (National Institute of Standards and Technology.) Accredited laboratories do not issue them. In fact, laboratories may not issue them because they have no relevance to the calibration service that was purchased and performed. The National Conference of Standards Laboratories (NCSL) is the body that defines most of the practices that calibration laboratories follow. Alliance Calibration’s policy is based upon the NSCL Position Statement 96-1. It states:
Test report numbers issues by the National Institute of Standards and Technology (NIST) of Of the United States Department of Commerce are intended to be used solely for administrative purposes. Although they are often used to uniquely identify documents which bear evidence of traceability, test reports should not be used nor required as proof of the adequacy of traceability of a test or measurement.
“Should not be used nor required” is definitive. To quote further form the NSCL Position statement:
It should be noted that nationally and internationally recognized standards dealing with test and measurement quality requirements such as ANSI/NCS Z540-1-1994, ISO 10012, ISO/IEC 17025, and the ISO 9000 series do not require the use or reporting of NIST Test Report Numbers to establish traceability.
A definition of traceability appears in the International Vocabulary of Basic and General Terms in Metrology, 2012, Section 2.43.
This sentence is also definitive.
“ISO/IEC 17025 and the ISO 9000 series do not require the use or reporting of NIST Test Report Numbers to establish traceability.”
ISO/IEC 17025 contains the general requirements for the competence of testing and calibration laboratories. Alliance Calibration is accredited by the Laboratory Accreditation Bureau (L-A-B), which provides accreditation services to independent metrology and calibration laboratories throughout the United States.
By established policy, accredited laboratories such as Alliance Calibration may only reference the unbroken chain of traceability to the SI Unit (International System of Units). Alliance Calibration does so in the boilerplate accompanying each calibration report.
Moreover, Alliance Calibration is required to use only accredited laboratories in its “unbroken chain of traceability.”
The use of accredited laboratories to create this “unbroken chain of traceability” confirms that our traceability has been verified as compliant with L-A-B policy.
Furthermore, this indicates our full cooperation with the regional and international cooperatives L-A-B participates in so that appropriate traceability to the International System of Units is maintained.