I agree. All of the symbols should be together. It should be correctly written as 30 $/kA.m. The $ sign looks really out of place when is is written as $30 /kA.m.
Jerry ________________________________ From: Pat Naughtin <[email protected]> To: U.S. Metric Association <[email protected]> Sent: Tuesday, April 7, 2009 7:40:22 PM Subject: [USMA:44467] Re: Strange SI units Dear John and Ezra, Two thoughts occur to me. 1How wonderful is the metric system? Here is an obscure application — getting the electrical energy form an off-shore wind energy source, and in a matter of moments the engineers can derive an appropriate unit, directly from the SI base units, that is coherent and the best fit for this application. 2Isn't it odd that the 'unit' for currency, dollar (symbol $), was fitted to numbers at the front rather than at the back; we write two dollars as $2 rather than as 2 $. In the application that Ezra found, it would make more sense, to me at least, if it was written as 30 $/kA·m with all symbols after the number. Cheers, Pat Naughtin Geelong, Australia On 2009/04/08, at 6:29 AM, John M. Steele wrote: 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 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 Pat Naughtin PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA. Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com/ or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter to subscribe.
