Planner doesn't care about MOD of first gas

Dirk Hohndel dirk at
Mon Jun 2 06:41:23 PDT 2014

On Mon, Jun 02, 2014 at 09:07:02PM +1200, Rick Walsh wrote:
> I tried to take up Dirk's challenge of breaking the latest master. I
> didn't manage that,

That's really good to hear :-)

> but I found a couple of issues with the planner.
> While the subsequent gas changes look like they're doing the right
> thing, it doesn't seem to care about the ppO2 of the first gas. See
> the attached screenshot, there is nothing telling me that taking 40%
> nitrox to 44m (a ppO2 of 2.2) may not be a good idea. You can take it
> to sillier values than that.

Correct. The manually added gases are not checked. You can turn on the
ppO2 graph and it will show you that you are doing something stupid, but
we are not doing anything beyond that.
Would be very easy to add, though.

> On a related note, is it possible to set a different max ppO2 for back
> gas and deco gas? I don't know the best way of going about this
> without making it overly complicated. Getting subsurface to tell the
> difference between the two may be an issue. Perhaps another column to
> the available gas table where the max ppO2 can be manually edited so
> the user can set a value of 1.4 for back gas and 1.6 for deco?

That's a good idea. Again, it adds to the configuration complexity, but
it's something that I do for my own diving, so it must be important :-)

> The other obvious thing in the attached screenshot, but I think this
> one is known, is that the gas pressure graph does not drop over the
> dive, despite having set my SAC, and cylinder size.

It should. I'll have to look into that.


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