The International System of Units (SI) is the modern metric system defined by the SI Brochure 1 , used/accepted worldwide. There are various 'style/usage guides' as to how to go about using, notating, manipulating the SI: The NIST guidelines interpret (and slightly modify) the SI specifically for the US (non-metric) commercial environment. The 'Americanization' of the SI by NIST for the Department of Commerce can be seen in additions/changes such as using wording from Webster's dictionary rather than Oxford dictionary (so, for example, using 'meter' rather than 'metre', 'deca' rather than 'deka', 'metric ton' rather than 'tonne', etc). 1, 2 ISO publishes an international consensus standard (ISO 31) promoting uniformity in the practical use of the SI, organized into 13 areas of science. 3, 4, IEC publish an international consensus standard (IEC 60027) promoting uniformity in the practical use of the SI for the electrotechnical industry. 3, 5 ISO 31 and IEC 60027 appear to be being harmonized and subsumed over time into ISO/IEC 80000. 8 IEEE/ASTM jointly developed an ANSI standard on the practical use of the SI in the United States. There are other similar technical organizations in other countries that publish similar standards for their countries. 4 This leads to a couple of questions on the scope/future of EMIX: Is this OASIS standard expected to be used internationally (outside the US)? Will this standard ever need/want to refer to units of measure beyond the electrotechnical industry? The answers to these two questions should inform us as to which of the above guidelines to the SIs would be the most practical for our use. For current purposes, giving us the broadest base and most future choices, UNECE 9 Recommendation 20 provides a full code list of ISO 31 / SI units that seems to include modifications for the US market such as noted above (e.g. 'metric ton' is included as well as 'tonne'). The document describing the code list development/structure:
http://www.oasis-open.org/committees/download.php/41532/rec20_Rev7e_2010.pdf Spreadsheet with data (name, symbol, description, etc) on over ~ 1600 units covering 13 areas of science. See sheet 'Annex I', rows 962 through 1061 (Electricity and Magnetism):
http://www.oasis-open.org/committees/download.php/41533/rec20_Rev7e_2010.xls Also note the column CONVERSION FACTOR , which may satisfy Aaron's recent request. Schema with all units/codes at
http://www.unece.org/uncefact/codelist/standard/UNECE_MeasurementUnitCommonCode_6.xsd . (schema includes codes/units from all Annexes (sheets) in the spreadsheet) (only the schema can be redistributed; the ss and pdf are informational only for this discussion) -Anne 1
http://physics.nist.gov/cuu/pdf/sp811.pdf , Appendix C.1 and
http://www.bipm.org/en/si/si_brochure/ 2
http://physics.nist.gov/Pubs/SP811/appenD.html 3
http://physics.nist.gov/cuu/pdf/SI_FRN_Notice_2008.pdf 4
http://physics.nist.gov/cuu/pdf/sp811.pdf , Appendix C.3 5
http://en.wikipedia.org/wiki/ISO_31 6
http://en.wikipedia.org/wiki/IEC_60027 7
http://physics.nist.gov/cuu/pdf/sp811.pdf , Appendix C.4 8
http://en.wikipedia.org/wiki/ISO/IEC_80000 9 United Nations Economic Commission for Europe Toby Considine wrote, On 3/10/2011 6:36 AM: 002701cbdf30$7fb39190$7f1ab4b0$@gmail.com type= cite > Thanks for the pointers. The following will be incorporated into numerous part of the documents and schemas, but for reference: IEC 60027-2, Second edition, 2000-11, Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics. Which can be publicly referenced at
http://physics.nist.gov/cuu/Units/prefixes.html and at
http://physics.nist.gov/cuu/Units/units.html “It is difficult to get a man to understand something, when his salary depends upon his not understanding it” -- Upton Sinclair. Toby Considine TC9, Inc OASIS Technical Advisory Board TC Chair: oBIX & WS-Calendar TC Editor: EMIX, EnergyInterop U.S. National Inst. of Standards and Tech. Smart Grid Architecture Committee Email:
Toby.Considine@gmail.com Phone: (919)619-2104
http://www.tcnine.com/ blog:
www.NewDaedalus.com