It is a kiloampere-meter. It is an alternate way to express an amount of wire. To carry a given current, a wire needs a certain cross-sectional area, but the area depends on what the wire is made of. A way to equalize and express costs across wire types is to rate by current carried, for each wire type that will require a certain area. Multiplied by the length of the wire, that gives volume and should be proportional to cost (at least fairly proportional). However, I don't think I've ever seen it before. I had to read the conext in the article to see what it is about. It is a clever way to relate the cost of the wire to its mission (carrying current for a distance) rather than purely by dimensions. It is analogous to looking at cost of fuels per unit of heat energy rather than by volume or weight. --- On Tue, 4/7/09, [email protected] <[email protected]> wrote:
From: [email protected] <[email protected]> Subject: [USMA:44462] Strange SI units To: "U.S. Metric Association" <[email protected]> Date: Tuesday, April 7, 2009, 3:46 PM #yiv411233063 p {margin:0;} Just came across this article: http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_62/iss_4/25_1.shtml but was flummoxed by this part: $30/kA·m What the heck is kA·m and why do they use it? Ezra
