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Tom, > If I read section 7.10.3 correctly, then I really should say something like: > 1e-6 dobson / dobson (or: 1e-6 mole/mole or 1e-6g/g or....) > for ozone concentration. Any of those would work because they all result in the dimensionless unit "1e-6". > The word I have from our scientists who deal with indirect > meassurements is that "ppm" is in very widespread use, and is likely > to show up in files, charts, publications, etc. I'm wondering if we > should not considering embracing this, just as we did "dobson"? I can easily add it to the UDUNITS-2 database. Should "ppm" be a name or a symbol? Name comparisons are case insensitive whereas symbol comparisons are case sensitive -- so "PPM" would be allowed if "ppm" were a name but not if it were a symbol. Once that's decided, then I can also add "ppb". > Thanks for consideration... > > tom > > -- > Tom Whittaker > University of Wisconsin-Madison > Space Science & Engineering Center (SSEC) > Cooperative Institute for Meteorological Satellite Studies (CIMSS) > 1225 W. Dayton Street > Madison, WI 53706 USA > ph: +1 608 262 2759 Regards, Steve Emmerson Ticket Details =================== Ticket ID: BAC-946054 Department: Support UDUNITS Priority: Normal Status: Closed