Re: Electroscope Materials

On Fri, 20 Jun 2008 12:36:29 -0500, "amdx" <amdx@xxxxxxxxxxx> wrote:

Why is gold used for the leaves in an electroscope?

Because gold is infinitely mallable and can be made VERY thin. If
you've ever handled gold leaf, you'll see why. The idea is for the
hinge point to be very flexible and the moving surfaces to be very
light.

Incidentally, you can get gold leaf at any art store. Just be VERY
careful how you handle it. Two sheets will permanently weld
themselves together if they touch.
<http://www.wisegeek.com/what-is-gold-leaf.htm>

In college, we tried to make a real gold leaf electroscope. We
finally got it working and found it amazingly sensitive. We could
detect a charged toy ballon at about 3 meters. However, we wrecked a
considerable quantity of gold leaf before we were able to produce a
working electroscope. The main purpose of the glass jar is NOT for
electrostatic isolation. It's to keep slight air movements from
trashing the gold leaf.

Is it just because gold can be made so thin?

Yep.

Conductive but light weight.

Yep.

What about aluminized mylar, or might the mylar continue to hold charge.
Mike

Thin Al foil from a chewing gum wrapper works ok. See:
<http://www.geocities.com/CapeCanaveral/Hall/1410/lab-GS-22.html >
Search Google for "aluminum foil electroscope". Aluminum is MUCH
easier to handle than gold, but because it weighs more, is less
sensitive.

--
Jeff Liebermann jeffl@xxxxxxxxxx
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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