Hi,

The breakdown field of air, or gas in general, is a function
of gas pressure times gap distance (Paschen curve). But it
depends on many other things too, like purity of gas,
humidity, electrode material, surface finish, and shape, etc.
So the breakdown field varies from case to case. For pure
air, the breakdown field is on the order of kilovolts per mm
at atmosphere. The best way to find out the breakdown
field of your setup is to do your own measurement with
different gas pressures and gap distances and plot your
own curves.
There is a book entitled "Gas Discharges". I forgot the author's
name but I can find out for you if you need it.

Tseng-Yang Hsu
Integrated Micromachines
[email protected]


-----Original Message-----
From: Wouter van der Wijngaart 
To: [email protected] 
Date: Thursday, April 16, 1998 7:35 PM
Subject: Electric breakdown of air


>Dear Sirs,
>
>I have been unsuccesfully searching for information on the dielectric
>breakdown field strength of air (gasses in general) at elevated
>pressures (1 -20 bar). The breakdown field rises for very small
>distances, but I could find no quantitative data. Has any of you found
>such ? All references are welcome !
>
>Thank you on forehand,
>
>Wouter
>
>Wouter van der Wijngaart
>
>Kungl. Tekniska H=F6gskolan Tel: +46 - (0)8 - 790 66 13
>
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>
>100 44  Stockholm Minicall: +46 - (0)740 - 26 71 28=20
>
>Sweden e-mail: [email protected]
>
>http://www.s3.kth.se/instrlab/staff/wouterw.html
>
>
>