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articles:nist_traceability [2019/11/20 07:47] – [An "unbroken chain of calibrations" to what?] rrandall | articles:nist_traceability [2020/01/15 15:09] – [An "unbroken chain of calibrations" to what?] rrandall |
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**FAA National Policy - Order 6200.4G** \\ | **FAA National Policy - Order 6200.4G** \\ |
Appendix 2 - Definitions \\ | Appendix 2 - Definitions \\ |
h. Calibration Standard - a device or instrument used as a basis to calibrate measure, gage, test, inspect, or otherwise examine basic accuracy values. The standard has a higher order of accuracy than the examined item and is traceable to the National Institute of Standards and Technology (NIST).</WRAP> | h. Calibration Standard - a device or instrument used as a basis to calibrate measure, gage, test, inspect, or otherwise examine basic accuracy values. The standard has a higher order of accuracy than the examined item and is __traceable to the National Institute of Standards and Technology (NIST)__.</WRAP> |
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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:\\ |
[[http://www.isobudgets.com/measurement-traceability-complying-iso-17025-requirements/|{{ :articles:measurement-traceability-pyramid-600px.jpg?direct }}]] | [[http://www.isobudgets.com/measurement-traceability-complying-iso-17025-requirements/|{{ :articles:measurement-traceability-pyramid-600px.jpg?direct }}]] |
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I describe the above pyramid as "//typical//" because, contrary to the antiquated language of ISO 9001:2015 & AS9100:2016, it is possible to “bypass” the National Metrology Institutes (NMIs) to obtain traceability to SI units. Using the example of DC volts, [[https://www.fluke.com|Fluke]], a world leader in the field of metrology, owns a [[https://nvlpubs.nist.gov/nistpubs/jres/095/jresv95n3p219_A1b.pdf|Josephson voltage system]], which they can use to realize the SI Units directly. | I describe the above pyramid as "//typical//" because, contrary to the antiquated language of ISO 9001:2015 & AS9100:2016, it is possible to “bypass” the National Metrology Institutes (NMIs) to obtain traceability directly to SI units. Using the example of DC volts, [[https://www.fluke.com|Fluke]], a world leader in the field of metrology, owns a [[https://nvlpubs.nist.gov/nistpubs/jres/095/jresv95n3p219_A1b.pdf|Josephson voltage system]], which they can use to realize the SI Units directly. |
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| Also, while not strictly speaking an 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 Member States. |
===== What are SI Units? ===== | ===== What are SI Units? ===== |
{{ :articles:2018-si.png?direct&130|}} | {{ :articles:2018-si.png?direct&130|}} |