The International System of Units (SI) is the modern metric system
defined by the SI Brochure1, 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.
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