Monday, October 3, 2016

Copper Wire Gauge, the Dummy Explanation

Measure diameter and gauge of copper wire with a wire gauge
Wire gauge for copper wire
Although occasionally our researchers at the Antisocial Network run across people who should know better saying stupid stuff, most of the time we metaphorically slap around people who just pretend to know what they're talking about. We should add that, unless the content makes a significant addition to the stupidification of the internet, we don't bother with people who say dumb shit for free. Be that as it may, nothing chaps our collective hiney like people who know so little about a topic that they don't even understand the question, but write about it anyway. Journalism and "communications" graduates are particularly prone to such antics, especially the ones like eHow.com's Nicole Schmoll. We caught up with Nicole as she was attempting to explain "How to Find the Diameter of a Copper Wire."¹

Nicole immediately launched into a basic discussion of the diameter of copper wires:
"Copper wires are categorized by their American Wire Gauge, or AWG, size. A wire's AWG size enjoys an inverse relationship with its diameter; the lower the AWG, the thicker the wire and the heavier the current load it is able to carry."
That's pretty much correct, and probably a near-perfect rewording of the wikipedia entry... we didn't look. While we found the creativity of "enjoys an inverse relationship" rather amusing, we had to wonder if anyone (and we do mean anyone) at eHow realized that "AWG size" is every bit as redundant as "PIN number" or "ATM machine." We doubt it...

Whatever the case, Scmoll goes on to instruct her readers to read the diameter of a wire's AWG from a gauge table. If you don't have a gauge table handy, Nicole advises you to:
"Remember that copper wire diameters increase and decrease by a factor of two every six gauges, three every 10 gauges, 10 every 20 gauges and 100 for every 40 gauges...."
...which, although a reasonable approximation, is quite clumsy. We note that Nicole fails to provide the formula for (approximate) diameter based on wire gauge, which (for inches) is
    
D = 0.005 * 92^((36-AWG)/39) 

But all of that's mere window dressing. We figure that since Schmoll had no concept of wire diameter before claiming this eHow title, she probably didn't realize that sometimes you don't know the gauge of a random hunk of copper wire... and that is a lot more likely question an amateur electrician might be asking. Some DIYer has a piece of wire and wants to know what diameter it is because he or she is at best only vaguely familiar with AWG. That person wants to measure the damned thing, because -- although Nicole apparently doesn't know this -- the AWG of a wire isn't generally stamped onto the metal (although it is often printed on the insulation, if any).
In that case, we'd want a tool called a "wire gauge" to measure the wire -- see above. Just stick the end of your mystery wire into a hole; if it's loose try the next smaller hole, etc. But Schmoll never mentioned this simple solution, preferring instead to hit her laptop with a bullshit stick. Well, that dog don't hunt, Nicole, and that's why you're our Dumbass of the Day. Enjoy!

¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was   ehow.com/how_7840505_diameter-copper-wire.html
copyright © 2016-2022 scmrak

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