I cannot help but think that the term 'metric ton' should be deprecated.
All SI units (with the exception of degree Celsius) are single name units.
Consequently their symbols are either usually single letters, or at most two
letters where the first is capitalized (e.g Pa). The main exception is
hectare (ha), but even that is really a unit plus a prefix. I've seen
metric ton symbolized/abbreviated to mt so many times I've lost count. But
you can see why people do it, and that is why I believe only tonne should be
used.
John F-L
----- Original Message -----
From: "James R. Frysinger" <j...@metricmethods.com>
To: "U.S. Metric Association" <usma@colostate.edu>
Sent: Monday, December 13, 2010 7:32 PM
Subject: [USMA:49182] Re: ASTM SI 10
We intend for it to be designated IEEE/ASTM SI 10-2010, Patrick. Not SI
10-2011.
The joint SDO committee for SI 10 reserves the option to diverge from the
SI Brochure and NIST SP 330 on the matter of style and non-SI units. But
it always adheres to the SI Brochure, as adapted by SP 811, regarding SI
units (base and derived) and prefixes.
Ironically, some of the balloters on the IEEE side of the table proposed
some actions beyond IEEE and ASTM authority, such as renaming the
kilogram, modifying prefixes, etc. Apparently they don't understand who
"owns" the SI; only the CGPM and its subsidiary administration can modify
the SI. Any other modifications would result in something that would no
longer be the International System of units (SI).
As a matter of style, people are free to not use portions of the SI that
they don't like. They can shun the prefixes hecto, deka, deci, and
centi -- but they cannot successfully assert that those are deemed
inferior by the SI community. Only the CGPM and its organization can do
that. That organization IS the SI community! That's what makes it
"International". Pat Naughtin could publish a document that omits the
centimeter or even deprecates it. But that would then be the Pat Naughtin
System of units (PNS), not the SI. Wisely, he seems not to have done that,
but instead he has opted merely not to use that lovely jewel (not to be
confused with "joule"!) of the SI.
Tables 1 through 5 define the SI. Yes, the degree Celsius is part of that!
SI 10 has not modified those.
Tables 6 through 9 list non-SI units, categorized by the view in which the
CGPM holds them. Table 6 is accepted for use with the SI by the CGPM and
its organization. Tables 7 through 9 provide other non-SI units that are
commonly used in certain narrow fields and are not deprecated there.
Indeed, some units related to items in Table 7 are about to become part of
the new base unit definitions! Table 9 contains items that most people are
hoping will go away and no longer be used. Table 8 is sort of in between
Tables 7 and 9 in that regard.
SI 10-2010 (not yet published) has made small changes to Tables 6 through
9. The hectare, liter, and metric ton (among others) remain intact. There
might be a few differences in specifications of style, as well. As we get
closer to release of the document more information on those will be
provided. Likely, I will submit an article to Metric Today in which I will
address those changes. Information will also be provided on how one might
obtain copies of the new SI 10.
Hopefully, everyone here on the list has joined USMA (the fees are
incredibly low) and thus receives Metric Today.
The roentgen and the curie are still listed in SI 10 Table A.1, which
contains conversion factors. So are the slug, the rhe, and the Btu.
Jim Frysinger
Chair, IEEE SCC 14
Vice Chair, IEEE/ASTM Joint Committee for Maintaining SI 10
On 2010-12-13 1228, Patrick Moore wrote:
Thanks for the update!
How is IEEE/ASTM SI 10-2011 different, by the way? Are references simply
revised to reflect a more recent version of BIPM? I am especially curious
whether the roentgen and curie are tolerated, though smelly. Also, are
celsius and liter still countenanced? Any changes where prefixes (deka-,
deci-, and centi-) are concerned?
Thanks again!
On 12/9/10 5:49 PM, "James R. Frysinger"<j...@metricmethods.com> wrote:
Dear Patrick -- and all!
The very next message in my inbox following this one of yours (by 22
minutes) was sent by IEEE staff, telling me that our proposed revision
to IEEE/ASTM SI 10-2002 was approved yesterday or today by the IEEE
Standards Association Standards Board. ASTM must also give its approval
since this is a joint standard. I am not authorized to speak
authoritatively for them, but I believe that they have in fact approved
it as well.
Much work remains to be done in the publication process (taking place at
IEEE), so it will be a few months until the new version (SI 10-2010) is
available at your local news stand.
Jim Frysinger
Chair, IEEE SCC 14
Vice Chair, IEEE/ASTM Joint Committee for Maintaining SI 10
On 2010-12-09 1500, Patrick Moore wrote:
Has any ASTM committee member among us learned the projected
publication date
for the ASTM SI 10 revision?
Thanks.
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(C) 931.212.0267
(H) 931.657.3107
(F) 931.657.3108
