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Re: 60 Gaps at 4 mil Data (fwd)





---------- Forwarded message ----------
Date: Tue, 14 Jul 1998 08:14:56 -0700
From: Jim Lux <James.P.Lux-at-jpl.nasa.gov>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: 60 Gaps at 4 mil Data (fwd)

Tesla List wrote:
> 
> ---------- Forwarded message ----------
> Date: Mon, 13 Jul 1998 20:40:49 -0700
> From: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: 60 Gaps at 4 mil Data (fwd)
> 
> Terry Fritz wrote:
> 
> > The power supply is a 900 watt neon.  I live in Colorado, the humidity
> > usually low.  I have noticed on humid days that the coil is more lossy.  On
> > a damp day, the secondary will ring down almost twice as fast as a dry day.
> > The spark length does decrease somewhat.
> 
> A question: Is the best tuning point affected by air humidity? As water
> is a very polar molecule, I would not find strange some change in the dielectric
> constant of air, and so in the capacitance associated with the terminal/coil and
> in the secondary resonance frequency.
> 
> Antonio Carlos M. de Queiroz

Standard humidity is only 7.5 g/cubic meter or 7.5g out of 1.3 kg, or
less than 1/2% water.

And, I think the high dielectric constant for water only applies to the
liquid and is because of the intermolecular forces from the highly polar
molecule. In air, the molecules are a long ways away from each other.

Interestingly, the breakdown voltage for air is higher with higher
humidity, even though water vapor is less dense than air (18 g/mol
compared to 29 g/mol). Probably because oxygen is electronegative.