I'm not sure...I did some work for Kodak years ago and they were using some
high purity stuff.  It was film manufacturing, not processing.

----------
> From: kent schnoeker <kentfoto@ad*.co*>
> To: Jess Armantrout <armantrout@wo*.at*.ne*>
> Cc: Russ Nolet <rnolet@un*.as*.co*>; p k <abyss30@ho*.co*>;
Techdiver <techdiver@aquanaut.com>
> Subject: Re: Isn't oxygen, oxygen?
> Date: Monday, November 29, 1999 9:10 AM
> 
> Jess,
>   Just curious, ...What photographic processes use helium?  I am familiar
> with 'nitrogen burst'. How does helium play a role?
> Thanks in advance,                                                       
Kent
> 
> 
> Jess Armantrout wrote:
> 
> > this is not correct.  There are many more grades of oxygen and helium.
> > There are lab grades with purities (and prices) you would not believe. 
For
> > example, if we had to use some of the helium used in photgraphic
processes,
> > we would all take up golf.
> >
> > The average person can get Medical o2 if he has a presciption to get
it.
> > This is not hard to get.
> >
> > Medical and aviators are identical, however, the av gas is guaranteed
to
> > have a lower dewpoint to prevent freezing at altitude.  The med gas is
> > guaranteed to meet FDA requirements.  In reallity, they are identical,
i.e.,
> > ABO would meet the FDA standard and USP would meet the dewpoint
standard.
> > The two gases, if fact, share the same MSDS.
> >
> > Ironically, in some high tech welding applications, the purity
requirements
> > for welding gas can be *greater* than that of breathing grades of
oxygen
> >
> > As has been stated before, all of the oxygen comes from the same place.
> > Cylinder prep and tracking procedures are the only differences.
> >
> > Oxygen, in and of itself is not explosive.
> >
> > Finally, reputable gas suppliers track lot numbers on both av gas and
med
> > o2.
> >
> > For much more information, see the Air Liquide and Air Products web
pages.
> >
> > Trout
> >
> > -----Original Message-----
> > From: Russ Nolet <rnolet@un*.as*.co*>
> > To: p k <abyss30@ho*.co*>
> > Cc: techdiver@aquanaut.com <techdiver@aquanaut.com>
> > Date: Sunday, November 28, 1999 11:27 AM
> > Subject: Re: Isn't oxygen, oxygen?
> >
> > >Yes, O2 is O2 (almost!).  The highest quality O2 that is available is
> > >Medical Grade, but the average person cannot get it.  The next grade
of O2
> > >is Avation Grade.  I do not know for sure exactly, but is most likely
> > >extremely similar in quality to medical except is not certified
medical
> > >grade (this is what I use to mix my gas).  The poorest quality is
welding
> > >grade, which is not monitored at all for quality, and is not required
to be
> > >filtered to remove particulate matter.  From a welding perspective the
> > >percentage of O2 in the tank is really not that critical.
> > >
> > >There are also different grades of helium.  The lowest grade is that
which
> > >is used for filling helium balloons, and should be avoided for diving
> > >purposes, welding grade which is the next step up is similar to
welding
> > >grade O2 in quality.  Military or medical grade helium is the one to
use
> > >because the gas is filtered and cylinders are controlled for quality
of
> > gas.
> > >
> > >The explosion/fire risk is essentially the same for each grade of O2. 
You
> > >are probably correct, most welders do not wash their hands, but the
risk of
> > >fire/explosion from changing an O2 reg with dirty hands is probably
nill.
> > >O2 is explosive when exposed to hydrocarbons at high pressure, any O2
> > >leaking from the reg or bottle valve is immediately reduced to 1atm
and
> > >diluted in the ambient atmosphere.
> > >
> > >An interresting anecdote: I am an engineer for a company that designs
> > custom
> > >test machinery to inspect for leaks in vessiles (gas tanks, evaporator
> > >cores, a/c compressors, etc...), we use a technology called Helium
Mass
> > >Spectrometry, where we fill the test object with helium tracer gas and
> > >"look" for heluim outside the test object.  A while back, I was
starting up
> > >a machine I designed, and I connected a Nitrogen tank to the test
object to
> > >confirm the machine cycle before introducing the helium which
sometimes
> > >causes another set of problems.  This time I kept getting what
appeared to
> > >be minor heluim leaks from the test opject.  After several hours, I
> > >determined that the nitrogen tank contained helium gas even though the
> > >bottle was the correct paint color to indicate nitrogen.  The most
> > important
> > >thing to be aware of when buying your own gas for mixing is to know
what
> > you
> > >are getting, and welding grade gasses are not controlled to the same
degree
> > >that the avation grades are.
> > >
> > >Russ Nolet
> > >
> > >----- Original Message -----
> > >From: p k <abyss30@ho*.co*>
> > >To: <techdiver@aquanaut.com>
> > >Sent: Saturday, November 27, 1999 8:05 PM
> > >Subject: Isn't oxygen, oxygen?
> > >
> > >
> > >> This question has plagued me for a while.
> > >> What is the difference between breathing oxygen and welding oxygen?
> > >>
> > >> First,I was told that welding O2 had more hydrocarbons contained in
> > >> it, BUT isn't the explosion/fire risk the same? How many auto
mechanics
> > >wash
> > >> and dry there hands before changing a regulator on an
> > >> oxy-acetylene torch? The second thing I was told is "there is
possibly a
> > >> higher moisture content", to me that doesn't hold up either because
> > oxygen
> > >> (commercial grade) will always come in a steel cylinder, if there is
any
> > >> moisture in there it will rust and pretty quickly I might add. So
what's
> > >the
> > >> deal? Anybody?
> > >>
> > >> ______________________________________________________
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