Re: field strength thoughts

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>


More like 1kV/m to 20 kV/m under a thunderstorm (esp, just before lightning)..

The field measurements are made by things like field mills, which, as Dave 
points out,  are very high impedance.

As to what happens when a large conductive object (i.e. person) is 
there?  The field is over a very large area, so you get a field 
concentration around the person, just like the concentration around a 
"breakout point" on a TC topload. Radius of curvature effects, etc.

Hence the inadvisability of standing up in a canoe on a salt marsh during a 
thunderstorm (or, waving that golf club in the air in Florida...)


On a more empirical note, having been in just such a situation, I can say 
that the field does concentrate around the uppermost point (yes, that 
tickling sensation on top of your head is your hair standing on end, and 
corona discharge from same).  You also get to see corona discharge off 
things with small radii of curvature (i.e. the point on your ice axe).

The field rapidly drops off after the stroke, too.. (at least, you don't 
notice the hair on end and corona effects as much..)


At 08:05 AM 3/10/2003 -0700, you wrote:
>Original poster: "davep by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><davep-at-quik-dot-com>
>
>Is there data indicating _rises_ at some level?
>
>'clear air/free space' field strengths can
>be 100-200V/M, higher during thunderstorms.
>
>What happens to the '1000V/M' readings if the
>operator is 'near' the field strength meter?
>
>(Field Strength measurements are typically 'high impedance'
>measurements: 'large bags of mostly water'  (people) tend
>to reduce them drastically.)
>
>best
>  dwp
>