Dear Gene, I have interspersed some remarks
on 2002-12-15 04.22, Gene Mechtly at [EMAIL PROTECTED] wrote: > My preference for this century is ton = metric ton = 1 000 kilograms, > as a string of three identically equal statements. One of the problems here is with the word 'ton' because it has, currently, many different meanings. Here are some of these. I can't be sure whether this list is exhaustive or if any of these are still in use somewhere in the world � there may also be many other kinds of tons in use. 1 ton (Imperial) = 1016.05 kg 1 ton (long) = 1016.05 kg 1 ton (short) = 907.185 kg 1 ton (US) = 907.185 kg 1 ton (force)(long) = 9964.02 N 1 ton (force)(short) = 8896.44 N 1 ton (refrigeration) = 3516.85 W 1 ton (refrigeration) = 3.515 85 kW 1 ton (volumetric) = 1 m^3* 1 ton (register) = 1 m^3* 1 ton (displacement) = 1 m^3* 1 ton (TNT equivalent) = 4.2 x 10^9 J* 1 ton (coal equivalent) = 3 x 10^10 J* 1 ton (oil equivalent) = 4 x 10^10 J* * Approximate As you can see these 'ton' units can measure mass, force, power, volume, or (several) different kinds of energy. > Ton = 1 000 kg is a well established definition of ton in most > countries (spelling variations aside), and is more explicitly related > to the SI base unit of mass, kilogram, than is megagram. I suspect that the reason we have the spelling 'tonne' is to differentiate a tonne of mass from a ton of something else (see list above). I also think that this is the same reason that the USA chose the term 'metric ton' to keep a metric tonne of mass distinct from the 'ton' morass (see list above). Of these two choices, I much prefer the simpler 'tonne'. > The Mg is unnecessary and is more of a deviation from coherent SI. The megagram is, in my opinion, the correct SI unit for the amount of mass that can also be referred to as a tonne (or as a metric ton in the USA) Cheers, Pat Naughtin CAMS Geelong, Australia > Gene. > ........................................ > On Fri, 13 Dec 2002, Pat Naughtin wrote: > >> Dear Terry and All, >> >> I agree that megagram, and its SI symbol Mg, is preferable to tonne. >
