[rossh]

Hello All,

New version v3.70 is now available. This release has the following;

• Partial pressure graphs Show you plan in terms of inspired ppInert values.
• MOD, EAN, best mix calculator Finds the most suitable mixes or MOD of a mix. Shows EAD, END - for OC and CCR.

The ppInert graphs are interesting to look at: See how the choices of diliuent change the inspired values or the swap to bailout mixes affect your plan.

Regards

[wedivebc]

Quote: (Originally Posted by rossh)

Hello All,

New version v3.70 is now available. This release has the following;

• Partial pressure graphs Show you plan in terms of inspired ppInert values.
• MOD, EAN, best mix calculator Finds the most suitable mixes or MOD of a mix. Shows EAD, END - for OC and CCR.

The ppInert graphs are interesting to look at: See how the choices of diliuent change the inspired values or the swap to bailout mixes affect your plan.

Regards

Here's a question. How come your software assumes O2 narcosis when calculating END? It used to give you the choice then you decided to fix it as O2 = narcotic. Since many agencies, feel this issue favours the other camp and since most Rebreather divers I know, feel from having experienced changes in narcosis level due to PO2 changes, maybe you should either remove the END altogether or return the choice option.
Just downloaded the new version and the best mix calculator also forces me to assume O2 = narcotic.

[rossh]

Quote: (Originally Posted by wedivebc)

Here's a question. How come your software assumes O2 narcosis when calculating END? It used to give you the choice then you decided to fix it as O2 = narcotic. Since many agencies, feel this issue favours the other camp and since most Rebreather divers I know, feel from having experienced changes in narcosis level due to PO2 changes, maybe you should either remove the END altogether or return the choice option.
Just downloaded the new version and the best mix calculator also forces me to assume O2 = narcotic.

In V-Planner you get the choice.. both are displayed throughout the program. Perhaps we have our terms crossed?

EAD = N2 only narcotic
END = both N2 and O2 narcotic

Regards

[wedivebc]

Quote: (Originally Posted by rossh)

In V-Planner you get the choice.. both are displayed throughout the program. Perhaps we have our terms crossed?

EAD = N2 only narcotic
END = both N2 and O2 narcotic

Regards

OK I see now your best mix calculator uses PPN2 for narcotic depth rather than 1-PPHE.
Sorry for the confusion.

[Steve]

Hi Ross,

Nice work yet again. Have you considered a gas density figure? I'm thinking of a figure that could sit next to the EAD that gives a Equivalent Air Density Depth (EADD) ie breathing 5/80 @ 150m is like breathing air @ 'x' m

This would be of particular use for very deep dives when factoring in gas breathability V's EAD V's CNS V's Deco considerations

As far as I know (please don't hold me to this) its a straight forward case of gas % x gas density at STP x pressure at depth = density at depth
Density of individual gases in kgs/m3 at STP is
O2 1.429
N2 1.250
He 0.179
CO2 1.977

eg density of air at 40m (O2 + N2)
(1.429 x 21% x 5ata) + (1.250 x 79% x 5ata) = 6.438 kgs/m3

eg 2 density of trimix 5/80 at 200m (O2 + He + N2)
(1.429 x 5% x 21ata) + ( 0.179 x 80% x 21ata) + ( 1.250 x 15% x 21ata) =8.4375 kgs/m3

Which gives an EADD of 58m

I think its important to at least be aware of this as breathing too dense a mix at depth can easily predispose one to CO2 accumulation. Gas selection is not just about ppO2 and narcosis. A figure indicatind the equivalent resistance of breathing air when diving very deep dives would be handy to know.

[cedricverdier]

Quote: (Originally Posted by rossh)

Hello All,

New version v3.70 is now available. This release has the following;

• Partial pressure graphs Show you plan in terms of inspired ppInert values.
• MOD, EAN, best mix calculator Finds the most suitable mixes or MOD of a mix. Shows EAD, END - for OC and CCR.

The ppInert graphs are interesting to look at: See how the choices of diliuent change the inspired values or the swap to bailout mixes affect your plan.

Regards

Hi Ross,

Very nice work. As usual with v-planner, the new version has some useful improvements. I definitely like the new pO2/pN2/pHe graphics. It's a wondeful teaching tool.

Cheers