The Hz is already used in engineering to denote one rotation. When I was helping the Poker Flat Research Range obtain a number of surplus Hydra-70 70 mm aircraft rockets from the US Army, I noticed in the performance specifications that the rockets' roll rate was expressed in Hz. The hertz is a perfect "drop-in" replacement for rpm. I think it isn't used more frequently in mechanical engineering because non-electrical engineers think of it as an electrical unit (just as many American MEs are reluctant to rate combustion engine power in watts because "everybody knows the watt is an electrical unit."). It's a matter of incorrect perception stemming from ignorance. -- Jason
----- Original Message ----- From: Ma Be <[EMAIL PROTECTED]> To: U.S. Metric Association <[EMAIL PROTECTED]> Sent: Tuesday, July 16, 2002 7:27 AM Subject: [USMA:21151] What can we replace rpm with?... > The post below got me thinking... I know we tried to get some discussion started here on this topic, rpm, but I'd like to see this issue revisited and hopefully come up with some consensus on this. > > I feel quite strongly that rpm is also another... "idiocy" we could do without (sorry, couldn't find a better adjective for it). If we are to think of this property as "periodical" we could certainly think of replacing it with Hz (or a prefixed "version" of it, like cHz or mHz). If we think of "rotational speed" (in angular form) then we'd be talking about this in rad/s, I'd think. > > Any ideas/suggestions from our technical gurus/experts here, please? Thank you kindly. > > Marcus > > On Mon, 15 Jul 2002 15:12:25 > Carter, Baron wrote: > >And of course if you go to the Citroen site www.citroen.com it is all metric > >including the English version. > > > >Baron Carter > > > >-----Original Message----- > >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > >Sent: Monday, 15 July, 2002 14:59 > >To: U.S. Metric Association > >Subject: [USMA:21116] New 'metric' car > > > > > >I am now the proud owner of a Citroen Picasso. For those unfamiliar > >with it, there is a totally digital dash. This was one of the > >attractions for me, as Citroen had previously told me that it could > >easily be set to metric. And so it can. There is a simple menu > >structure, that allows setting of language, date, time (12 or 24 h), > >and units. So I now have a car which tells me how many km I can go on > >remaining fuel (diesel, by the way), how many km I've travelled in > >total and on the trip, how many l/100 km I am using, etc. > > > >As well as that, it's a very nice car! > > > >Chris > > > >-- > >UK Metric Association: http://www.metric.org.uk/ > > > > > > > Is your boss reading your email? ....Probably > Keep your messages private by using Lycos Mail. > Sign up today at http://mail.lycos.com >
