Re: UNITS

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

Original poster: Jan Wagner <jwagner-at-cc.hut.fi> 


On Sun, 1 Feb 2004, Tesla list wrote:
 > Original poster: "Crow Leader" <tesla-at-lists.symmetric-dot-net>
 > The AWG system makes sense, there is never confusion about "are you talking
 > diameter or cross sectional area" as with metric.

Not so. The unit of "area" is still ~to unit of "length" squared, no
matter which system, thus there _shouldn't_ be any confusion between
these even if you're accustomed to US or Imperial or some other system.

0.8mm   = length, e.g. diameter
0.8mm^2 = area, e.g. cross sectional area,
                 e.g. a square with sqrt(0.8)*1mm sides

 > We do have MCM for large
 > wires, but again, it's simple - MCM = 1000 circualr mils, that's it.

"Simple" is probably a source for endless & useless debate... ;o)

Using multiples of .0000007854inches^2 as a unit for surface
area is very cumbersome. Given a square wire of 10 MCM to fit
through a wall, how long are the vertices of the hole to make?
Or similarly, given 5 AWG, what's the diameter? Quick now, hurry up! ;)

(yeah this is a useless post, i know, i know... ;) )

cheers,

  - Jan

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