high humidity increases the breakdown voltage of air, increasing the amount
of charge that can be carried by a given sized particle or object.
high humidity also DECREASES the surface resistance of most objects, causing
whatever charge is there to leak off faster. This is why electrostatic
machines work better on dry days (and why you don't get "shuffle across the
carpet" sparks on wet days). Very clean electrostatic machines with properly
chosen insulators work just fine in 90% humidity.
This one comes up all the time when looking at spark gap voltage humidity
correction tables.
In the case of charging of antennas and wires, I think that there would be a
host of confounding factors that would make it hard to say which effect
would be larger. I would guess that the leakage current would dominate. The
variation of surface resistance with humidity is orders of magnitude. The
variation of breakdown voltage is a few percent.
If one were clever, one should be able to build a Kelvin water dropper type
apparatus that charges when it rains.
----- Original Message -----
From: "Keith Dutson" <kjdutson@earthlink.net>
To: "TowerTalk" <towertalk@contesting.com>
Sent: Wednesday, September 01, 2004 2:38 PM
Subject: RE: [TowerTalk] snow static, Quad v. Yagi
> Have you ever made observations of this charge buildup under varying
> humidity? I am wondering if higher relative humidity decreases the charge
> potential and vice versa.
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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