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articles:nist_traceability [2019/01/26 14:47] – [An "unbroken chain of calibrations" to what?] rrandallarticles:nist_traceability [2019/05/19 11:25] – [What are SI Units?] rrandall
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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 SI Units are also explained on the NIST web site at: https://www.nist.gov/pml/weights-and-measures/metric-si/si-units
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 +And, alternatively, are presented in "[[https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication330e2008.pdf|NIST Special Publication 330 -  The International System of Units (SI)]]" (which will likely be updated after May 20, 2019).
  
 Because SI units are derived from intrinsic (i.e., invariant) constants of nature, "intrinsic measurement standards" exist. This is acknowledged in ISO 17025:2017, sec. 6.5.2, which provides 3 (three) different methodologies for achieving metrological traceability. And is further clarified in ISO 17025:2017, "Annex A: Metrological traceability". \\ Because SI units are derived from intrinsic (i.e., invariant) constants of nature, "intrinsic measurement standards" exist. This is acknowledged in ISO 17025:2017, sec. 6.5.2, which provides 3 (three) different methodologies for achieving metrological traceability. And is further clarified in ISO 17025:2017, "Annex A: Metrological traceability". \\