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Date: Fri, 29 Dec 1995 08:56:43 -1000 (HST)
From: Dennis Pierce <epic@so*.ha*.ed*>
To: Richard Pyle <deepreef@bi*.bi*.Ha*.Or*>
cc: "George M. Irvine III" <gmiiii@in*.co*>, techdiver@terra.net
Subject: Re: Semi Closed Rebreather

ahhhh, very good job, both of you !!!


On Fri, 29 Dec 1995, Richard Pyle wrote:

> > >This is the "Steady State" Semi-closed equation, and applies to constant
> > >mass-flow type semi-closed rebreathers. It assumes a constant workload
> > >(metabolic rate), constant loop volume, and that inert gas absorbed by the
> > >body and other constituaents in the loop are negligible. 
> > >
> > >      Rich, could you please give me the formula for what the stock 
> >        market is going to do tomorrow, and will this work down at Calder
> >        Race track as well? - G
> 
> George's point is very well taken.  I provided the formula, but that 
> doesn't mean the formula has any representation of reality. I want to 
> start up the "don't put too much faith in numbers" thread, but we've 
> heard it all before.  If you read my report on the PNG trip, you'll know 
> that my diving partner and I have very different metabolic rates, even at 
> the same workload.  With the enormous range of physiological variability 
> in the population, precise numbers having to do with such things as 
> decompression schedules, oxygen toxicity, FiO2 inside a semiclosed 
> rebreather loop, scrubber canister durations, etc. etc. etc., are silly 
> and potentially dangerous. You have to look at formulas and numbers in 
> diving as rough guides at best.
> 
> So, yes, that formula is the formula for calculating steady-state FiO2 in 
> a constant mass flow type semi-closed rebreather; however, it's only as 
> useful as you have confidence in your metabolic O2 consumption rates at 
> various workloads.  From my experience, I would have very little 
> confidence in my own metabolic rates for using such a formula.
> 
> Aloha,
> Rich
> 
> P.S.:
> 
> *******************************************************************
> "WHATEVER happens to you when you willingly go underwater is
> COMPLETELY and ENTIRELY your own responsibility! If you cannot
> accept this responsibility, stay out of the water!"
> *******************************************************************
> 
> --
> Send mail for the `techdiver' mailing list to `techdiver@terra.net'.
> Send subscription/archive requests to `techdiver-request@terra.net'.
> 

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