RE: Lightning Storm

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

On 24 Jul 2005, at 23:10, Tesla list wrote:

> Original poster: "keith" <keith.cc@xxxxxxxxxxx>
>
> You can use a device called an electric field mill to measure the
> magnitude of an electric field, which can give a decent indication of
> the likelihood of a lightning strike. Here's all of the substantive
> websites I managed to find on this when I was researching it a few
> months ago (it seems to be a pretty obscure device)
> http://www.precisionstrobe.com/jc/fieldmill/fieldmill.html
> http://www.sciam.com/article.cfm?articleID=00000ED3-69CA-1C72-9EB7809E
> C5 88F2D7 http://www.ee.nmt.edu/~langmuir/E100/E100.html
> http://www.boltek.com/efm100.htm
>
> Seems like it would be fairly easy to build for someone with a bit of
> experience in electronics, and is apparently not too difficult to
> calibrate accurately.

> Keith C

On the face of it it looks simple enough to build but the choice of
motor is important. Brush noise can easily drown out signals in the
pA range as I found when I tried it.

Malcolm