I'm looking for an electric field mill, a little gadget usually
with rotating vanes that measures the electric field in the air
above the device.  As one rotating set of vanes covers and uncovers
the insulated fixed vanes below a tiny change in voltage on the
insulated vanes gives an easily calibrated and stable measure of
the electric field above the device.

I want to measure variation in atmospheric fields over the year.

There are several example hobby projects on the net where these
have been built by amateurs.

Scientific American had many of the details of building one of these
in the July 1999 issue. I have photocopies of that and can provide
those if needed.  This was available on the internet but they seem
to have blocked access to this now. But this involved spinning one
metal office trash can inside another at close distances and at
7000 rpm.  My guess is that with my mechanical skills if I tried
to do this and videotaped it I could easily end up on an episode
of "World's Stupidest People."

Another hobby field mill is described here:

http://www.precisionstrobe.com/jc/fieldmill/fieldmill.html

Some commercial field mills, but I'd prefer to not pay this much:

http://www.provantage.com/buy-22096112-boltek-efm-100-atmospheric-electric-field-monitor-lightning-detector-shopping.htm

Someone else suggested:
"Take a look at New Mexico Tech Langmuir Lab website. Their EE
department build them. Plenty of detail, including circuits. They're
not difficult to make, if you have machining facilities (or even
if you don't, and don't mind a bit of crudity). Calibration is a
breeze."

And someone else suggested:
"There is a chance you can find some old ones that were replaced
or upgraded.  Check out http://surplus.ksc.nasa.gov/.  They are
responsible for disposing of all kinds of scientific and industrial
equipment that is surplus to the Space Program."

I've been searching Ebay for months without success.  Electrometers
show up but I'm not so sure about pressing one of those into service,
and I may not want this to be 110 ac powered.

I'm either looking for a used/surplus working mill or having someone
build the hardware.  I might handle the electronics involved in the
project, or not, depending on what the agreement would be.  I would
discuss costs with whoever might be interested in working on this
and see whether it makes sense for everyone involved.

If you are interested, or you know anyone else who might be, I would
greatly appreciate discussing getting this project done.

thanks
don
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