On 4/13/2011 2:52 PM, Steve Emmerson wrote:
On 04/13/2011 02:25 PM, John Caron wrote:
the point im trying to make is that it would be better to understand
that "mol mol-1" (canonical udunit = 1) is not the same as "m3 m-3"
(canonical udunit = 1).
In my opinion, the distinction between "mol/mol" and "m3/m3" is better
indicated by the name of the physical quantity being displayed rather
than by its unit attribute. In the cases under consideration, the
respective physical quantities would be "amount of substance fraction"
and "volume fraction".
See Table 12 of<http://physics.nist.gov/Pubs/SP811/sec08.html> for more
information.
For example, the Y-axis of a plot could be labeled "Amount of Substance
Fraction of Carbon / 1e-9" to plot nanomoles of carbon per mole of whatever.
Regards,
Steve Emmerson
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Hi Steve:
Thanks, that a useful reference. It may be that some extension to
udunits following Table 12 could solve most of the issues.
Im thinking that ne wants a grammer that allows
"mole <X> / mole" * "mole/ mole <X>" = 1
"mole <X> / mole" * "mole/ mole <Y>"= "mole <X>/ mole <Y>"
and so on.
I wonder if this list could accumulate a list of such examples.
John
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