Possible Bug with Stats and Info

[Linus Torvalds]

On Mon, May 8, 2017 at 11:47 AM, Ryan McLean <pvtryan100 at gmail.com> wrote:
> I performed a side-mount dive with 2x10L 232 Bar Steel Cylinders added in
> the Equipment Page as two separate line items
>
> On both tanks:
> Starting Pressure: 200
> Final Pressure: 120
> Dive Time (62m 20Sec)
> Max Depth 7.2m
> Avg Depth: 5m
>
> Looking at the info Page I see:
> ********
> Gases Used
> Air
> Air
>
> Gas Consumed
> 720L

Yeah, you don't have a gas switch event, so subsurface thinks the
second tank is basically unused.

> When I look at the Stats Page I see
> ********
> Gas Comsumed:
> 720L

Same thinghere.

You can add a fake gas switch event on the profile, and you'll get the
expected numbers, I think.

I do *not* know what the right model for "use two cylinders at the
same time" is, although the other hack (right now) is to simply
consider your dual cylinders to be one single one (of twice the size).
But that only works when the beginning/ending pressures match (like
they happen to do for you), ie when you can basically consider the
side mount cylinders to be one single combined manifold.

Although your expected numbers are kind of wrong:

> Gas Consumed
> 800L
> 800L
>
> SAC
> 17
>
> Gas Comsumed:
> 1600L
>
> SAC
> 17

Your 800l is wrongly calculated.

You seem to think that one atmosphere is 1 bar. That's not true.

You also don't take the compressibility of air into account.

I suspect the subsurface number of 720.9l per cylinder is actually the
correct one. You can hover over the equipment fields to see the actual
conversion to liters at the pressures in question.

                     Linus