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Christina_Young@Wa*.Me*.co* writes:
> 
> Lippmann does mention K&S and the serial compartment model.  I
> think that it may be easier to reverse engineer than a parallel
> compartment one.  About actually doing it, how about just sucking the
> actual tabular values into Mathematica and reconstructing the
> "decompression surfaces"?  You could do a surface fits on them.  The
> resulting model would be entirely empirical.

I'm not sure why the serial compartment model would be easier to
reverse-engineer than a parallel model.  If you simply mean to create
an empirical model, given only table inputs, then you will have a hard
time predicting intermediate values not on the tables if you don't
know the model at all.

The parallel models are actually very easy to reverse-engineer.  I and
Dave Waller have done it for several popular computers, and gotten
pretty close to what must be the real values for those computers,
given our results.  We could never have done this (with tolerable
accuracy) if we didn't have a clear idea how the model itself worked
PLUS the halftimes of their compartments.

Rob Sartin and I are investigating the DCIEM model and it is not
simple.  Add to that the reported hacks they've applied to get the
tables to behave (naughty DCIEM didn't fix their own model), and you
get into a situation where you can make a model, but not an accurate
model.  Fun, but not satisfying.

> Any comments about this?  I'm just toying with this idea.  Perhaps to account
> for the different inert gases, the surfaces would have multipliers based upon
> the solubility of the gas (they would modify the surface gradients)?  This is
> very interesting stuff!

I'm not sure what you mean by "surface gradients," but it is indeed
accepted practice to assume different inert gases are non-conflicting,
and that they vary in solubility by the square of their molecular weights.

Cheers,

David Story                        NAUI AI Z9588, PADI DM 43922, EMT
story@be*.en*.sg*.co*            Better diving through computers.

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