Re: UNITS

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Ed Phillips <evp-at-pacbell-dot-net> 

Tesla list wrote:
 >
 > Original poster: dhmccauley-at-spacecatlighting-dot-com
 >
 > Its just the opposite here.  If someone says 14AWG, 20AWG, 30AWG, i know
 > exactly what that wire is.  When you guys start quoting wires in mm, i often
 > find
 > myself converting to see what the equivalent AWG gauge is.
 >
 > Dan
 >
 >  > yes. When we started using S.i. I found electronic calculations much
 >  > more logical, all the formulas made sense and not so many
 >  > co-efficients.Still I battle when sombody talks in "AWG" instead of mm,
 >  > etc, if you say 1mm winding wire I know what it means but 22AWG means
 >  > nothing to me.

	I think it's all a matter of what we're familiar with.  I was brought
up on both cm and inches, but all engineering units were inches for
dimensions.  Doesn't matter if you can make the conversions correctly.
By the way, several years ago I had occasion to work with Mitsubishi on
a possible radar installation in one of their MU-2's.  They sent
drawings which had an interesting feature.  Although they're supposed to
be a full metric (and SI?) country, station dimensions were given in
millimeters, in some cases up to 25000 (not 25 meters or 2500 cm!).

	Things like 4 pi can never be eliminated.  Push them down one place and
they pop up in another.  For some things decimal dimensions are
convenient and for others fractions are better.  Interesting to note
what units Tesla used when and as he mentioned them as in CSN.
Sometimes cm, sometimes feet, sometimes mixed!  He knew his conversions
and wasn't hung up on unit system.

Ed