Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)
Peter wrote:
> My application was a deep sub-sea project at very high pressures. I
> can guess that at high pressure the air will turn to liquid and that
> will certainly stop the drive working. And in a vacuum the head will
> simply scrape over the surface of the disc as there will be no
> aerodynamic behavior at all. Somewhere in the middle a disc drive
> operates within spec.
If you're going to be designing systems to work at high pressure, you need
to familiarize yourself with the physics of the situation before you do
anything.
Air will not liquefy at _any_ pressure until the temperature gets below the
critical temperature of one of its components, and the critical
temperatures for all the major components of air are more than 100C below
the freezing point of sea water.
When you are doing engineering, do not _guess_.
At that kind of pressure I doubt that the sealed mil-spec drives would hold
up--while they'll take some pressure they aren't designed for those levels.
You need to either make a pressure vessel to hold the drives or you need to
go to an alternative technology that is not dependent on a specific range
of air pressures.
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
Peter wrote:
> My application was a deep sub-sea project at very high pressures. I
> can guess that at high pressure the air will turn to liquid and that
> will certainly stop the drive working. And in a vacuum the head will
> simply scrape over the surface of the disc as there will be no
> aerodynamic behavior at all. Somewhere in the middle a disc drive
> operates within spec.
If you're going to be designing systems to work at high pressure, you need
to familiarize yourself with the physics of the situation before you do
anything.
Air will not liquefy at _any_ pressure until the temperature gets below the
critical temperature of one of its components, and the critical
temperatures for all the major components of air are more than 100C below
the freezing point of sea water.
When you are doing engineering, do not _guess_.
At that kind of pressure I doubt that the sealed mil-spec drives would hold
up--while they'll take some pressure they aren't designed for those levels.
You need to either make a pressure vessel to hold the drives or you need to
go to an alternative technology that is not dependent on a specific range
of air pressures.
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
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