Fwd: Re: [PATCH] Fix up SAC calculations for ATM/bar confusion

[Chris Lewis]

>>
> As an example one real dive: Double7/300, pressure from 260 to 10 bar.
> Subsurface says I used 3500 litres but Suunto Dive Manager 3176,4 litres.
> It's a 9 % error.
>
> I'd like to see some correction, but I agree using gas-mix and
> temperature sounds too much. But, one day, someone will send a patch . . .
> Jukka
>
>

The reality is that the temperature in the cylinder is a mystery to us.
Sure we can assume local ambient temperature at the start of the dive
(assuming no solar heating effects) but then what is the temperature of the
gas in the cylinder during the dive.
We would have to account for both cooling due to immersion of the cylinder
in water and adiabatic effects of dropping pressure inside the cylinder.

All seems more hassle than its worth. I would suggest some simple
correction factor over a certain pressure.

Chris
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