Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!cs.utexas.edu!uunet!mcvax!ukc!castle!aipna!edai!cam
From: cam@edai.ed.ac.uk (Chris Malcolm    cam@uk.ac.ed.edai   031 667 1011 x2550)
Newsgroups: sci.electronics
Subject: Re: Touching a "hot" connector
Keywords: touch, sensation, live, shock
Message-ID: <498@edai.ed.ac.uk>
Date: 5 Aug 89 02:39:21 GMT
References: <89Jun8.160452edt.10877@ephemeral.ai.toronto.edu> <814@corpane.UUCP> <427@edai.ed.ac.uk> <1528@sunset.MATH.UCLA.EDU>
Reply-To: cam@edai (Chris Malcolm)
Organization: University of Edinburgh, Edinburgh
Lines: 30

I'd like to thank all those kind people who have expressed concern for
my continued existence, given my habit of touching live wires to see if
they are live. Snoopy (snoopy@sopwith.UUCP) kindly provided these facts:

From _Electronic Components and Measurements_ by Bruce D. Wedlock and
James K. Roberge, based on an article entitled "The Fatal Current,"
originally published by Fluid Controls Corporation:

"...currents between 100 and 200mA are lethal... The actual body
resistance varies depending on the points of contact and the condition
of the skin.  The total resistance may be as low as 1kOhm for wet skin
and as high as 500kOhm for dry skin."

Well, as I promised, I tested my resistance. As I said I have dry skin.
With a light touch. such as I use for testing mains, my resistance is
>10MOhm. If I dampen my fingers by breathing on them, and grab the test
prods painfully firmly, I can bring it down to around 10KOhm. That's
still an order of magnitude under the lethal current. So you all kind
folks can stop worrying about me! As a matter of fact, the kind of jolts
I sometimes inadvertently get from the mains are not as severe as the
jolts I can get from old diathermy machines, which doctors used to use
to administer therapeutic shocks to gullible patients. Nor are they as
severe as holding an electric fence of the cattle retaining kind.

Does anyone know what would happen if one inadvertently, one rainy
night, with wet feet, pissed onto an electric fence?
-- 
Chris Malcolm    cam@uk.ac.ed.edai   031 667 1011 x2550
Department of Artificial Intelligence, Edinburgh University
5 Forrest Hill, Edinburgh, EH1 2QL, UK