Suggested new units for udunits.dat

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Suggested new units for udunits.dat
• From: Harvey DAVIES <hld@xxxxxxxxxxxx>
• Date: Fri, 28 Jul 1995 17:05:46 +1000 (EST)

Here are some suggested new units for the units database file 'udunits.dat'.

CONSTANTS section currently defines 'percent' and '%'.  I suggest also
ppt                     S 1.0e-3                # parts per thousand
ppm                     S 1.0e-6                # parts per million
ppb                     S 1.0e-9                # parts per billion
ppt                     S 1.0e-12               # parts per trillion

This section also currently defines 'bakersdozen' as 13, which I assume is
included just for fun.  However it may be worthwhile including some other
common words for numbers such as:
pair                    P 2
ten                     P 10
dozen                   S 12
score                   S 20
hundred                 P 100
thousand                P 1.0e3
million                 P 1.0e6
billion                 P 1.0e9
trillion                P 1.0e12


UNITS OF LENGTH section currently defines 'printers_point' & 'printers_pica'.
I suggest changing definition of latter from
printers_pica           P 4.217518e-3 meter
to
printers_pica           P 12 printers_point     # exact

I suggest allowing following aliases
point                   P printers_point
pica                    P printers_pica
pc                      P printers_pica
The abbreviation 'pt' is often used for printers_point, but this is already
defined as pint!

Another important printing unit of length is the 'big point', as used in
PostScript.  This has the abbreviation 'bp'. So I suggest:
big_point               P inch/72               # exact
bp                      S big_point


UNITS OF TIME section currently defines 'fortnight', but not 'week' or 'month'!
I suggest following:
week                    P 7 day
month                   P year/12               # mean calendar month
lunar_month             P 29.530859 day
sidereal_month          P 27.321661 day
tropical_month          P 27.321582 day


I hope at least some of these are considered useful enough to be included in
'udunits.dat'.


Harvey Davies,                              Home: +61 3 9772 5199
CSIRO Division of Atmospheric Research,     Work: +61 3 9586 7574
Private Bag No. 1, Mordialloc,               Fax: +61 3 9586 7600
Victoria 3195,  Australia                 E-mail: hld@xxxxxxxxxxxx