Re: Corrected di-el strength of gas

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

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 

What is the source of the list?

I'm curious, because air has a widely accepted breakdown voltage of around
3kV/mm, and you give 0.97.
Is this for a needle gap? (which would have about 1/3 the breakdown for a
uniform gap)

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, May 04, 2004 6:36 AM
Subject: Corrected di-el strength of gas


 > Original poster: "john cooper" <tesla-at-tesla-coil-dot-com>
 >
 > I posted an error for the di-electric strength of air in a previous
 > response, the 0.4-0.7 for air was kV/mm.  Here's a new partial listing for
 > some gasses (FWIW gases and gasses are both proper)
 >
 > Air, 0.97
 > Argon, 0.18
 > Carbon Dioxide, 0.82 - 0.88
 > Carbon Monoxide, 1.02 - 1.05
 > Chlorine, 1.55
 > Helium, 0.15
 > *Hexafluoroethane, 1.82 - 2.55
 > Hydrogen, 0.50
 > Methane, 1.00 - 1.13
 > Nitrogen, 1.00
 > Neon, 0.16 - 0.25
 > Nitrous Oxide, 1.24
 > *Octafluoropropane, 2.19 - 2.47
 > *Sulfur Hexafluoride, 2.50 - 2.63
 > Tetrachloromethane, 6.21 - 6.33
 >
 > *used in industry and research as di-electrics
 >
 > The di-el strength of a gas is measured as a comparison to Nitrogen - 1.0
 > It was surprising for me to realize that air, which doesn't provide much
 > quenching, is rated at 0.97; while Nitrogen, which quenches quite well, is
 > rated at 1.00  Not much of a difference in rating for a huge difference in
 > quenching ability.
 > Neon & Helium could be an interesting alternatives to Argon for inducing
 > long streamer length although neon is more expensive than helium.  Someone
 > asked about CO2, they'd be better off with compressed air.
 >
 >
 >
 >
 >