My table, which Bill has kindly posted at www.metric1.org/nonsi.htm, is a
list of Non-SI [i.e., wombat] units, not a list of "non-metric units." There
is a big difference between "metric" and "SI" because the great majority of
metric units are not SI.
One of the interesting things the table shows is that most of the Non-SI
units used in the USA are not "English." A third of them are metric or world
customary units. Another quarter were invented here in the USA. Only about
one-sixth are British colonial units, and nearly all of those originated on
the continent, not in England. Another fifth are Anglo technical units
invented after the industrial revolution (mostly in Britain).
Another purpose of the table was to contrast the simplicity of SI (only 30
named units) with the vast collection of non-SI units used in America (>300,
including many different units for the same quantity--as many as 50
different units, often of confusingly similar size). The great advantage of
SI is that it has ONE AND ONLY ONE unit for every quantity.
Following Adrian's suggestion, we will, as time permits, add alternative
entries in the Abbreviations column, including the "correct" ones when a
standard exists (as in the case of km/h). But, as Bill has noted, one of the
purposes of the table was to show how irrational, illogical, slangy, and
inconsistent our wombat abbreviations are, since the public knows many units
only by their abbreviations. For example, the BTU labels on appliances
actually mean Btu/h (power), not Btu (energy).
The symbol L for liter was adopted by the CGPM in 1979 because the old
lowercase el (l) symbol, adopted in 1879, was routinely confused with the
numeral 1. We have been told that the capital L symbol began in Australia.
It is now the officially preferred symbol in the U.S and Canada too. For the
time being, the antiquated lowercase el is still allowed by the CGPM,
presumably because hidebound Europeans refuse to give it up. But I look
forward to the day when it is prohibited. Incidentally, the loopy script el
which Europeans sometimes use to avoid the 1 vs. l confusion is NOT approved
by any body.
> -----Original Message-----
> From: Adrian Jadic
>
> I looked at the table and I observed also kilometer per hour. First, it
is
> incorrectly abbreviated as kph, second I beleive it creates
> confusion to put
> it in a list of non-metric units as it is a metric unit.
> Maybe we should include something that would explain the slang
> denomination
> known as kph (kay pe aytch) instead. Or, maybe we should include
> a separate
> list of metric units that are incorrectly used, abbreviated, pronounced,
> etc.
> I don't know what the others think, but I would remove kilometer per hour
> from the list.
>
> In SI, capitals are used only for units that represent a proper name
(Joule,
Ampere, Hertz etc.). Is there an objective reason for using L instead of l
in North America?
