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2008 Editions of NIST SP 330 and SP 811 Available

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  • 2008 Editions of NIST SP 330 and SP 811 Available

    These two documents are the fundamental definition for the SI (metric system) as used in the United States. SP 811 also includes an excellent set of conversion tables in the Appendix.

    Note: The links in the original article lead to the 2008 versions as pdf files. At the NIST site, the link to SP 811 still leads to 1995 version. I've reported error.

    New edition of metric-system guide published
    By William Jackson

    We all know that in the movies, “the fundamental things apply, as time goes by.” But in the real world, the fundamental things are continuously being updated, refined and redefined so the National Institute of Standards and Technology has published a new U.S. edition of the “International System of Units” — better known as the metric system.

    NIST Special Publication 330 is the U.S. version of the English language text of the eighth edition Le Système International d' Unités (SI), the standard reference to the International System (SI) published by the International Bureau of Weights and Measures. The most recent U.S. edition was published in 2001. The revised guide includes changes made since 1998, including a new chapter on units for quantities describing biological effects, and symbols for expressing values for enzyme catalytic activity in biology and medicine.

    The metric SI has never really caught on with U.S. consumers, who measure automobile performance in miles per gallon rather than kilometers per liter, but it is the common language of scientific and technological research. The U.S. Omnibus Trade and Competitiveness Act of 1988 and the America Competes Act of 2007 establish it as the “preferred system of weights and measures for [U.S.] trade and commerce.”

    The secretary of Commerce has the responsibility of interpreting the SI for the United States. The U.S. version standardizes the American spelling of some English words using the United States Government Printing Office Style Manual, which follows Webster's Third New International Dictionary rather than the Oxford Dictionary. The spellings “meter,” “liter,” and “deka” are used rather than “metre,” “litre,” and “deca.” And it is a “metric ton” rather than “tonne.” On the numerical side, the decimal marker used in this country is a dot or period, but in France it is a comma.

    The new edition also establishes a new unit and symbol for the mol; the symbol “kat” for katal, which expresses values of the quality of catalytic activity; and new units for describing biological effects. All recent decisions by international standards bodies that affect the SI are included.

    NIST also has published a companion document, Special Publication 811 titled “Guide for the Use of the International System of Units” to help authors with correct SI usage and unit conversion. It also includes an editorial checklist for reviewing manuscripts for conformity with the system.

  • #2
    The BIPM has issued a 2014 supplement to the 8th Edition, SI Brochure. Half the document is the French text, with English text in the back half.

    The changes include:
    * Some formalisms in the order of base units in the definition of derived units.
    * Formal recognition of the IAU definition (2012) of the astronomical unit as an exact value in meters, and promotion from Table 7 to Table 6.
    * Refinement of some experimentally-determined values in Table 7 to agree with 2010 CODATA including the electron volt and dalton (unified atomic mass unit).

    NIST should issue a supplement to SP330, but in the meantime, these changes should all be applicable to SP330. Users should be mindful of American spelling, meter, liter, metric ton; this supplement uses British spelling, but, otherwise, I think it applies verbatim to NIST SP330..
    Last edited by JohnS; 07-27-2014, 09:54 AM.