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From: "William E. Sadler" <yqwyktp@bl*.bs*.co*>
Subject: Re: What's the last word on nitrox stratification? (fwd)
To: techdiver@terra.net (Techdiver Mail List)
Date: Mon, 19 Jun 95 13:57:39 EDT

Jim,

> Well, I rolled the tank for a few minutes, re-checked with the
> Mini-Ox, and sure enough, the FO2 had gone up by a few percentage
> points. After a few more minutes of rolling, the FO2 had risen to
> what my "target" was, after which it leveled off (note that I did not
> adjust the calibration on the Mini-Ox at any point).
> 
> I have only observed this phenomenon just the one time with that one
> tank, but since I could not come up with any other explanation for
> what I observed, then I assume it must have been the result of
> stratification.
> 
> So now I am a Believer. Any Doubters out there care to shoot holes in
> what I saw?

This is not stratification, this is insufficent time for the gases to blend.

When you have a quantity of pure O2 in a tank, and you inject air, you will
get eddies and pockets of each gas individually, and you will get some mixed.

As time goes by, the gases will migrate within each other, and will form
the blend you are looking for.

Right after filling, it will be luck as to what you're measuring w/ the minox.

Gases that will stratify will tend to form layers with time, as opposed to
migrating into a homogenous blend.

So, O2 and nitrogen do NOT stratify, but must have time (or mixing) in order
to blend.

Hope that makes it clearer!
--
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/* William E. Sadler  | email:  sadler_b@bs*.bs*.bl*.co*                */
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