Engineers and Meterologists: Has Anyone Built an Electrostatic Field Mill?

I had good luck with using 10, 10 meg surface mount resistors in series in an electrostatic amplifier.

Just in case you haven't seen this:-

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

Randall. Thanks for your help and comments. Yes I have seen that information. Shawn Carlson's original Scientific American article was the start of my interest in this project. There have been some other developments in the state of the art that have been recently published, but I cannot locate them.

Double ended motors with the position sensor and shaft grounding on the bottom have been suggested to help reduce interference from the sensor signal. (this requires another (smaller) rotor. (or a 5 :1 phase locked loop)

Shawn used a DC motor and had problems with brush noise. The addition of the synchronous rectifier is a natural filter to all frequencies (except aliasing harmonics)

I guess you have to have really built one to better understand the pitfalls.

Snakers

"Please, if you do not know what a field mill is, do not comment."

Do I know what an electrostatic field mill is? Yes, indeed I do, all too full well!

It has been a long time ago when model airplanes were built to be flown on braided stainless wire control lines. Around and around, up overhead, and flown in reverse direction upside down. There was a distant dark cloud a mile or two away yet the 50 ft. control lines picked up the static charge directly overhead. The plane was then flown at near ground level till out of fuel and safely landed. There is nothing like a first hand experience with your own personal version of an EFM!

It should be noted than no fancy high gain amplifier, sheet metal work, etc. was necessary to achieve noticeable results.

Other post(s) link to DIY EFM projects.

I've had enough of EFM's. You can get your kicks from building a fancy one.

Wikipedia say a large Field Mill is located in Mansfield England.

Under www.qsl.net/dh1stf you find a lot of information, unfortunately written in German.

Regards Uwe

Have a look here:

http://freespace.virgin.net/paul.z/Electronic/fieldmill1.htm