# Measurements using field probe

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-----Original Message-----
From: terryf-at-verinet-dot-com <terryf-at-verinet-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Date: Wednesday, July 01, 1998 8:28 AM
Subject: Re: Measurements using field probe

Hi Antonio,

You are correct.  I left out the Ca in the first equation because is is
normally insignificant.  The other equation you give with the 4 factor is
also correct.  I miss typed.  A real calibration against some known
measurement is always better.

Terry Fritz

At 11:06 PM 6/30/98 -0500, you wrote:
>
>----------
>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
>results.
>
>Antonio Carlos M. de Queiroz
>
>

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