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Alliance Calibration Blog

The Calibration Bench | Blog

NIST Numbers: Your Auditor Is Wrong.

Posted by Phil Wiseman on Jan 1, 2020 12:19:05 PM

I thought the topic of NIST numbers had been resolved when we published What you need to know about NIST numbers.

 

I was wrong!

We received a phone call last week from a customer asking for our NIST number as their auditor/assessor had requested it prior to their upcoming audit.

We advised this customer that "NIST number" is not a valid measure of traceability and should not be requested by an auditor.

They were having no part of it so it is time to write another article on NIST numbers.

NIST specifically addresses this issue in Supplementary Materials related to NIST Policy on Metrological Traceability:

"I.B.4 Is a NIST Test Report Number necessary and/or sufficient evidence of traceability?

Test report numbers issued by NIST are intended to be used solely for administrative purposes. Although they are often used to uniquely identify documents which bear evidence of traceability, test report numbers themselves do not address the issues listed inI.B.1above, and should not be used nor required as the sole proof of traceability."
 
NIST also states:
 

Requirements for Laboratory Accreditation Bodies

Under the EMC/Telecom MRAs, NIST designates qualified US-based testing laboratories to specific foreign requirements. The testing laboratories must be accredited by a US laboratory accreditation body listed by NIST. To be listed by NIST, the laboratory accreditation body must be recognized by and in good standing with a laboratory accreditation cooperation (i.e. ILAC, APLAC, etc.) that verifies, by evaluation and assessment, that its members are in full compliance with ISO/IEC 17011 and that their accredited laboratories comply with ISO/IEC 17025.
The laboratory accreditation body must have appropriate assessor expertise to assess and accredit emc/telecom laboratories and must undergo witness audits by technical experts to verify that the relevant technical requirements are being properly assessed.
The following U.S. laboratory accreditation bodies are acceptable for use for the purpose of the NIST MRA designations under various EMC/Telecom MRAs:
 
View Requirements for Laboratory Accreditation Bodies
Source: https://www.nist.gov/standardsgov/accreditation-bodies-mras

 

Quality Magazine addressed NIST numbers in 2010.

Quality 101: Traceable to NIST, Explained

"Referencing the NIST Number

Many imported gage certificates will state that equipment used for inspection is directly traceable to NIST and then a NIST test number will follow. Having a NIST test number is only a reference number for tracking internal documents at NIST. But how does one know its specific application?

Again, the NIST definition for test numbers helps explain.

“Test report numbers issued by NIST are intended to be used solely for administrative purposes,” NIST says. “Although they are often used to uniquely identify documents which bear evidence of traceability, test report numbers themselves do not address the issue and should not be used nor required as the sole proof of traceability.”

The International Accreditation Service also addresses this in POLICY GUIDE ON CALIBRATION, TRACEABILITY, AND MEASUREMENT UNCERTAINTY FOR CALIBRATION LABORATORIES 

"NOTE: NIST Test Numbers, sometimes known as “NIST numbers” are not valid for ensuring or demonstrating traceability. The report or certificate numbers provide the documentation of the path of traceability. It is noted that some calibrations from NIST do not include specific report numbers. In these instances there must be sufficient information to link that specific NIST number to that specific calibration. An example of the information can include the date of calibration and specific description of the item calibrated by NIST under that NIST number."

 JM Test Systems also addresses this issue in NIST NUMBERS… WHAT ARE THEY?

"A2LA’s policy on the use of NIST numbers as evidence of traceability is also in line with the policy of the National Conference of Standards Laboratories (NCSL). “It is the position of the National Conference of Standards Laboratories (NCSL) that:

Test report numbers issued by the National Institute of Standards and Technology (NIST) 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 report numbers should not be used nor required as proof of the adequacy or traceability of a test or measurement. 

It should be noted that nationally and internationally recognized standards dealing with test and measurement quality requirements such as ANSI/NCSL Z540-1-1994, ISO 10012, ISO/IEC Guide 25, and the ISO9000 series do not require the use or reporting of NIST test report Numbers to establish traceability…

I need NIST numbers on my Certificates of Calibration.  Can you provide that for me?

No.  Test report numbers issued by NIST are used solely for administrative purposes. Test report numbers themselves do not address traceability and should not be considered as the sole evidence of traceability. Test report numbers should not be used nor required as proof of the adequacy or traceability of a test or measurement. It should be noted that nationally and internationally recognized
standards dealing with test and measurement quality requirements such as ISO/IEC 17025 and ISO 9000 series do not require the use or reporting of test report numbers to establish traceability."

NCSL issued a statement on NIST numbers in 1996 with Position on the Purpose! and Appropriate Use of NIST Test Report Numbers.

"It is the position of the National Conference of Standards Laboratories (NCSL) that:

Test report numbers issued by the National institute of Standards and Technology (NIST) of the United States Department of Commerce are intended to be used solely for administrative purposes. Although they are often used to identify documents which bear evidence of traceability, test report numbers should not be used nor required as proof of the adequacy or traceability of a test or measurement. It should be noted that nationally and internationally recognized standards dealing with test and measurement quality such as 2540-I-1994, 10012, Guide 25, and the 9000 series do not require the use or reporting of Test Report Numbers to establish traceability. A definition of traceability appears in the International Vocabulary of Basic General terms in Metrology, 1993, Section 6.10."

The problem in resolving this issue is the lack of Accreditation Body oversight in calibration laboratory marketing. Do an internet search for NIST traceable calibration and you see that calibration laboratories use this in their marketing. In addition, when an accreditation body sends an Auditor they have a responsibility to train them in traceability.

If your Auditor/Assessor asks for a NIST number, they are not properly trained by their Accreditation Body. Did they have to pass a test?  Yes, I am saying it and let the chips fall where they may.

Accreditation Bodies require Assessor Training that includes traceability.

Course Description

The 4.5-day ISO/IEC 17025:2017 Lead Assessor training course is designed to further develop your understanding of ISO/IEC 17025 and help you understand how to plan and lead an ISO/IEC 17025 assessment. Attendees will gain an understanding of uncertainty, traceability, and PT/ILC and how they are assessed. This course will prepare you to meet technical demands of being an assessor while providing practical exercises to aid comprehension. Attending an ISO/IEC 17025 Lead Assessor Training course is just one of the necessary steps in becoming a contract assessor for an accreditation body.*

https://anab.ansi.org/training/17025/lead-assessor

NOTE: I am NOT implying that this particular assessor is associated in any with ANAB/ANSI.

You may want to read ILAC Policy on the Traceability of Measurement Results  for a deeper understanding of traceability to the SI unit and the role of National Metrology Institutes such as NIST.

Do not ask for a NIST number!

Measurements have always been essential in supporting international trade and regulation. They are required for the underpinning of conformity with written standards, and measurements have also stimulated innovation and advances in technology as well as in human well-being.

Many millions of measurements are made each day. Ideally, all should be traceable to national reference standards so as to ensure international consistency and long-term stability. This was originally the task of national metrology institutes (NMIs), or their historical equivalents. In 1875, the need for international consistency in measurements was recognized and formalized by the Metre Convention.

During the 1960s the NMIs recognized the importance of creating a system through which they might assess and validate the technical competence of other organizations which need to make, and demonstrate traceable measurements. This led to the emergence of the accredited laboratory sector, and to the International Laboratory Accreditation Cooperation (ILAC).

Source:https://www.bipm.org/en/cipm-mra/cipm-ilac_joint_statement.html

 JOINT BIPM, OIML, ILAC and ISO DECLARATION ON METROLOGICAL TRACEABILITY states:

"The International Laboratory Accreditation Cooperation (ILAC) aims to promote the mutual recognition of test and measurement certificates issued by laboratories accredited by national accreditation bodies to internationally accepted standards for technical competence. ILAC members are peer evaluated and become signatories to the ILAC Arrangement. The ultimate aim of the Arrangement is increased use and acceptance by industry as well as governments of the results from accredited laboratories, including results from laboratories in other countries. In standards such as ISO/IEC 17025, metrological traceability of measurement results to primary realizations of the SI (often referred to as national measurement standards) is required, and in other similar standards traceability should either be to the SI or to other agreed international references where SI traceability is not, or not yet, possible."

Quality Digest explains What Is Measurement Traceability?

"NIST’s website directly addresses their policy toward traceability. It states: “NIST does not define, specify, assure, or certify metrological traceability of the results of measurements except those that NIST itself provides.” Which basically means that NIST makes no claims on the traceability of measurement results unless they were directly measured by NIST. The policy further states that supporting traceability claims is the responsibility of the measurement provider. Taken together, this implies that no organization may claim that NIST will confirm a measurement result to be traceable to NIST. Rather, it is up to the organization that performed the measurement to prove through calibration documents that traceability is linked to NIST. For example, at the end of the calibration chain, a length standard may have been used that is calibrated by NIST and has a document of calibration."

There is absolutely no reason a properly trained Auditor/Assessor should ever ask for a NIST number.

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