The liter is not an SI unit, but it is a "unit in use with SI." Moreover, it is not in the group described as "Units in use temporarily with SI." Therefore there is no plan to either phase out or deprecate its use.
The liter is exactly a cubic decimeter -- by definition! The old discrepancy was because of the old definition, which was the volume of a kg of water at a certain temperature. That definition was discarded long ago. (I don't plan to look up the year.) The hectare is one of the ones "in use temporarily." I think it's a useful size and, therefore, I favor its use. Others may differ. In relation to SI, I haven't seen a definition of "temporarily." I guess, in the cosmic sense, we can argue that everything is temporary. Bill Potts, CMS Roseville, CA http://metric1.org [SI Navigator] >-----Original Message----- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] >Behalf Of Gavin Young >Sent: Friday, February 20, 2004 19:09 >To: U.S. Metric Association >Cc: U.S. Metric Association >Subject: [USMA:28829] Re: litre and hectar are not SI units > > >Clarify why you say the litre is not part of SI. Has it been >replaced with the >cubic decimeter because of the slight difference between the two >(as detected >by precise modern equipment), or is it because cubic decimeters and cubic >meters meters make the liter (litre) unneeded? Likewise why is the >hectare not >to be used. Are we supposed to say 10,000 square meters or 100 >ares instead of >hectare? > >Quoting Bill Hooper <[EMAIL PROTECTED]>: > >...... > >> >> Regards, >> Bill Hooper >> Fernandina Beach, Florida, USA >> >> PS Some other units that you may be surprised to learn are NOT units of >> the SI system are: >> the litre >> the tonne (metric ton) >> the hectare >> the bar (and, by inference, the millibar) >> the calorie and >> the micron. >> >> > > >Gavin Young >http://www.xprt.net/~hightech , http://www.renewableelectricity.com, >http://www.electric-automobile.com >
