Switching gas's

[deep_diver1967]

My dive profile starts at an altitude of 5000 feet, dry suit and a single steel HP 100 with 28% O2. I have a Al 20 cu ft pony also with me as my redundant air supply. I use it at a "deco" bottle and breathe if down to 500 psi, as way of reducing nitrogen for the next dive.

there are no deco dives, with NDL dropping to maybe 5 minutes with an ATA of 1.4. per dive.

The question is: when I setup the Atomic to switch gas at 60 ft, it does prompt me for the switch gas confirmation.
When I acknowledge, and do switch regs and tanks ( second tank (pony) is not on ATOMIC integrated computer), the ATOMIC returns to "guage" mode... grey out items on screen... as per the manual description.

With out air intergration, is the ATOMIC still properly calculating the proper nitrogen level, O2 levels, such that I could enter the water again with "accurate" NDL time for the next dive?

I have switched back to my main tank ( 28% O2) from the pony, during the dive and the ATOMIC picks up the dive where it had left off using the 28% O2. Is it calculating correct?

This is not described in the manual, or on other forums clearly.

 

[Dr. Lecter]

The manual covers it clearly enough for me:

"Cobalt will use planned gas switches when calculating no-deco times and surfacing schedules. Switching away from your primary gas mix will disable the gas time remaining calculations. This and the tank pressure reading will be shown in a grayed text color whenever you are not using the primary mix."

Simply put, if you tell it you switched, it will grey out the data related to the pressure on the main tank (because that's no longer the gas pressure from which you're breathing and no longer controls air time remaining) AND it will start calculating N2/O2 info based on the switched-to mix. Tell it you switched back to the main tank and it'll start calculating the N2/O2 info based on that mix, and because the pressure info becomes relevant again it's no longer grayed out.

AI info is irrelevant to deco/O2 loading calcs.

 

[RonR]

...
When I acknowledge, and do switch regs and tanks ( second tank (pony) is not on ATOMIC integrated computer), the ATOMIC returns to "guage" mode... grey out items on screen... as per the manual description.

With out air intergration, is the ATOMIC still properly calculating the proper nitrogen level, O2 levels, such that I could enter the water again with "accurate" NDL time for the next dive?

I have switched back to my main tank ( 28% O2) from the pony, during the dive and the ATOMIC picks up the dive where it had left off using the 28% O2. Is it calculating correct?

This is not described in the manual, or on other forums clearly.

Dr. Lecter is correct. The Cobalt doesn't have a "gauge mode" where it stops doing deco calculations. The grayed out pressure and gas time remaining is just to indicate that this information, while still displayed (and updated), is not relevant to the gas you are using. Deco calculations are continuing based on whatever mix you have selected. And, as you said, if you switch back to the "primary" mix, GTR calculations will pick up again. You could, in fact, dive the Cobalt as a non-integrated computer, and still switch between gas mixes- three in the Cobalt 1, six in the Cobalt 2.

Ron