DDC Fixed Head Disks

Chuck Guzis cclist at sydex.com
Sun Jun 10 16:59:33 CDT 2007

On 10 Jun 2007 at 13:58, jd wrote:

> Not too long ago a 5ft cylinder of 99.995% helium @ 3600psi costs $75.00 plus
> whatever deposit and demurrage, and the same cylinder of 99.95% argon @ around
> 1200psi cost around $100.00. There's much more helium in the cylinder than argon.
> I'm sure nitrogen was more expensive. I remember thinking that it was odd that
> common nitrogen was so much more expensive than helium.

My thought was that helium would diffuse out through the tiniest 
opening or porous seal quite rapidly.  On the other hand, argon 
doesn't even come close to helium's thermal conductivitiy.


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