Measurements using field probe

From:  Antonio Carlos M. de Queiroz [SMTP:acmq-at-compuland-dot-com.br]
Sent:  Tuesday, June 30, 1998 11:05 PM
To:  Tesla List
Subject:  Re: Measurements using field probe

Terry Fritz wrote:

First, congratulations for your excellent work. I have just the few observations
below. Please correct me if I am not seing something.

> These are the equations that govern the voltage and current probe outputs:
> Voltage Probe
> Vov = ( Ca / Cl ) Vs

Vov = Ca/(Ca+Cl) Vs, but the difference is small.
> Current Probe
>         Voc = Rl ( Aa / (pi x R^2) ) ) Is

Voc = Rl ( Aa / (4 x pi x R^2) ) Is, as the surface area of a sphere is 4 x pi x R^2.

> Note that the area between the coil and the antennas should be free from
> large objects and such that may disturb the electrostatic fields being
> picked up.

Ideally, this includes the ground and the secondary coil. Due to this, these 
measurements may vary significantly depending on where the probes are (side
of the coil, top of the coil). A calibration procedure is necessary for accurate

Antonio Carlos M. de Queiroz