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articles:nist_traceability [2020/01/23 10:03] – [Traceability to Organizations, rather than SI Units] rrandallarticles:nist_traceability [2021/11/10 06:49] – [What are SI Units?] rrandall
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-**[[https://www.nist.gov/document/gmp-13-ensuring-traceability-20180213docx|NIST GMP 13, "Good Measurement Practice +**[[https://www.nist.gov/system/files/documents/2019/06/21/gmp-13-ensuring-traceability-20190621.pdf|NIST GMP 13, "Good Measurement Practice 
 for Ensuring Metrological Traceability”]], sec. 1.1 (3rd para.):** \\ for Ensuring Metrological Traceability”]], sec. 1.1 (3rd para.):** \\
 "//Test numbers issued by NIST should not be used nor required as proof of the adequacy or traceability of a test or measurement. Having a NIST number does not provide evidence that the measurement value provided by another organization has the property of metrological traceability.//" "//Test numbers issued by NIST should not be used nor required as proof of the adequacy or traceability of a test or measurement. Having a NIST number does not provide evidence that the measurement value provided by another organization has the property of metrological traceability.//"
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 And And
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-**[[https://www.nist.gov/document/gmp-13-ensuring-traceability-20180213docx|NIST GMP 13, "Good Measurement Practice  +**[[https://www.nist.gov/system/files/documents/2019/06/21/gmp-13-ensuring-traceability-20190621.pdf|NIST GMP 13, "Good Measurement Practice  
-for Ensuring Metrological Traceability”]], sec. 1.3.3, "Use of, or reference to, official test numbers of a national metrology institute":** \\  +for Ensuring Metrological Traceability”]], sec. 1.6.3, "Use of, or reference to, official test numbers of a national metrology institute.":** \\  
-"//Having an authentic test number does not provide assurance or evidence that the measurement value provided by another organization is traceable. Not only must there be an unbroken chain of comparisons, but each measurement must be accompanied by a statement of uncertainty associated with the value. Test report numbers should not be used nor required as proof of the adequacy or traceability of a test or measurement. National and international standards dealing with test and measurement quality requirements, such as ISO 10012, ISO/IEC 17025 and the ISO 9000 series do not require the use or reporting of specific test numbers to establish traceability.//"+"//Having an authentic test number does not provide assurance or evidence that the measurement value provided by another organization is traceable. Not only must there be an unbroken chain of comparisons, but each measurement must be accompanied by a statement of uncertainty associated with the value. Test report numbers should not be used nor required as proof of the adequacy or traceability of a test or measurement. National and international documentary standards for test and measurement quality requirements, such as ISO 10012, ISO/IEC 17025 and the ISO 9000 series, provide guidance for assessing metrological traceability and do not require the use or reporting of specific test numbers to establish metrological traceability.//"
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 This is further noted in the: This is further noted in the:
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 Sec. 820.72 Inspection, measuring, and test equipment. \\ Sec. 820.72 Inspection, measuring, and test equipment. \\
 (b) (1) Calibration standards. Calibration standards used for inspection, measuring, and test equipment shall be __traceable to national or international standards__. If national or international standards are not practical or available, the manufacturer shall use an independent reproducible standard. If no applicable standard exists, the manufacturer shall establish and maintain an in-house standard.</WRAP> (b) (1) Calibration standards. Calibration standards used for inspection, measuring, and test equipment shall be __traceable to national or international standards__. If national or international standards are not practical or available, the manufacturer shall use an independent reproducible standard. If no applicable standard exists, the manufacturer shall establish and maintain an in-house standard.</WRAP>
 +
 +Similar antiquated language appears in [[http://everyspec.com/MIL-STD/MIL-STD-1300-1399/MIL-STD-1309D_87/|MIL-STD-1309D]], (12 February 1992), which doesn't even recognize international standards or offer alternatives where no national measurement standards exist:
 +<WRAP center round box 80%>**MIL-STD-1309D, "Definitions of Terms for Testing, Measurement and Diagnostics"**\\
 +3.1.653 Traceability. The ability to relate individual measurement results to __national standards or nationally accepted measurement systems__ through an unbroken chain of comparisons.
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 In contrast, ISO 17025:2017 is much more modern and technically correct in stating:\\ In contrast, ISO 17025:2017 is much more modern and technically correct in stating:\\
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 Also, while not strictly speaking a National Metrology Institute (NMI), the [[https://www.bipm.org|"Bureau International des Poids et Mesures" (BIPM)]] offers [[https://www.bipm.org/en/bipm-services/|calibration & Measurement services]] (with traceability to SI Units) to its [[https://www.bipm.org/en/about-us/member-states/|Member States]]. In that instance, the BIPM would serve as equivalent to a NMI. Also, while not strictly speaking a National Metrology Institute (NMI), the [[https://www.bipm.org|"Bureau International des Poids et Mesures" (BIPM)]] offers [[https://www.bipm.org/en/bipm-services/|calibration & Measurement services]] (with traceability to SI Units) to its [[https://www.bipm.org/en/about-us/member-states/|Member States]]. In that instance, the BIPM would serve as equivalent to a NMI.
 +
 +Transcat has an excellent White Paper on this topic at: [[https://www.transcat.com/calibration-resources/white-papers/what-is-measurement-traceability]].
 ===== What are SI Units? ===== ===== What are SI Units? =====
 {{ :articles:2018-si.png?direct&130|}} {{ :articles:2018-si.png?direct&130|}}
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-SI Units are also explained on the NIST web site at: https://www.nist.gov/pml/weights-and-measures/metric-si/si-units and in "[[https://www.nist.gov/pml/special-publication-330|NIST Special Publication 330 -  The International System of Units (SI)]]". Both NIST sources will likely be updated soon to reflect the new definitions to the SI that went into effect on May 20, 2019. +SI Units are also explained on the NIST web site at: https://www.nist.gov/pml/weights-and-measures/metric-si/si-units and in "[[https://www.nist.gov/pml/special-publication-330|NIST Special Publication 330 -  The International System of Units (SI)]]". 
 ===== What are "intrinsic" standards? ===== ===== What are "intrinsic" standards? =====
  
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 NIST, for example, is a non-regulatory agency of the United States Department of Commerce. When the US Government was "shut down" during 1995, 2013, 2018, and 2019, NIST operations were suspended. So if your company had measurement standards at NIST awaiting calibration, or if you outsourced calibration to a metrology lab who had its measurement standards at NIST, then the length of time associated with the government "shutdown" was added to the delay in receiving those instruments. These government "shutdowns" create a "ripple effect" throughout industry. NIST, for example, is a non-regulatory agency of the United States Department of Commerce. When the US Government was "shut down" during 1995, 2013, 2018, and 2019, NIST operations were suspended. So if your company had measurement standards at NIST awaiting calibration, or if you outsourced calibration to a metrology lab who had its measurement standards at NIST, then the length of time associated with the government "shutdown" was added to the delay in receiving those instruments. These government "shutdowns" create a "ripple effect" throughout industry.
  
-To avoid this, standards writing bodies and regulatory agencies should gain a better understanding of "metrological traceability" and allow other NMIs and/or accredited commercial metrology laboratories to be utilized in providing metrological traceability to SI units.+To avoid this, standards writing bodies and regulatory agencies should gain a better understanding of "metrological traceability" and allow other NMIs and/or accredited commercial metrology laboratories to be utilized in providing metrological traceability to SI units. In particular, these bodies should promote international consistency of measurements through adopting the recommendations of the [[https://ilac.org/latest_ilac_news/joint-bipm-oiml-iso-and-ilac-declaration-on-metrological-traceability-signed/|"Joint BIPM, OIML, ISO and ILAC Declaration on Metrological Traceability"]].
  
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 For more information visit: [[https://us.flukecal.com/literature/about-calibration]] For more information visit: [[https://us.flukecal.com/literature/about-calibration]]