Re: Oxygen saturation concentration

To: Aquatic-Plants at actwin_com
Subject: Re: Oxygen saturation concentration
From: George Booth <booth at hpmtlgb1_lvld.hp.com>
Date: Tue, 25 Jun 1996 16:01:49 -0600
In-Reply-To: Your message of "Tue, 25 Jun 1996 15:39:04 EDT." <199606251939.PAA15056 at looney_actwin.com>

> From: psears at NRCan_gc.ca (Paul Sears)
> Date: Tue, 25 Jun 1996 08:35:04 -0400 (EDT)
> 
> 	This oxygen concentration corresponds to the equilibrium
> between oxygen in solution and the oxygen in the air.  It corresponds
> to an oxygen partial pressure of about 0.2 atmospheres.  If you want
> oxygen bubbles to form, you need a local concentration corresponding
> to 1 atmosphere pressure of oxygen, i.e. thirty-odd mg/litre.
> 
> 	The word "saturation" has to be used carefully - it must be
> clear what the other phase is; in this case a bubble of oxygen gas at
> 1 atmosphere.

OK, I'm confused.  I see bubbles forming at around 110% of saturation.
The dissolved O2 is measured with a Lamotte kit and then compared with
a chart I have which shows saturation at something like 6.1 mg/l (from
memory) at my altitude.  Are we talking two different things here?

George