Default FO2 Setting Clarification on T3

[checkyourmirrors]

I just got my Nitrox certification and I am looking to set starting the settings on my T3 but I have to say after reading the manual on the gas settings and default FO2, I am confused as to what it means or how it works.

Does anyone have a better explanation that what is in the manual?

From what I found out on the Oceanic website (basically same as Aeris) it is a worst case fail-safe override. It seems to mean that after ever dive it changes the gas mix to 50% from whatever setting you did your previous dive at. Meaning if you dive at EAN36 it will set it to EAN50 trying to make sure you are way over conservative.

Seems odd to me and one could easily forgot to reset the mix. Is this right?

 

[ronbeau]

I just got my Nitrox certification and I am looking to set starting the settings on my T3 but I have to say after reading the manual on the gas settings and default FO2, I am confused as to what it means or how it works.

Does anyone have a better explanation that what is in the manual?

From what I found out on the Oceanic website (basically same as Aeris) it is a worst case fail-safe override. It seems to mean that after ever dive it changes the gas mix to 50% from whatever setting you did your previous dive at. Meaning if you dive at EAN36 it will set it to EAN50 trying to make sure you are way over conservative.

Seems odd to me and one could easily forgot to reset the mix. Is this right?

You are correct. I have this option set to Off on my Aeris ATMOS AI and T3.

 

[bperrybap]

From what I've read, it sets the O2 *and* N2 values to an impossible situation.
50% O2 and 79% N2. So you are uptaking oxygen *and* N2 much faster than normal.
I do know that if you accidentally take a dive in this mode,
it makes for a shallow dive dive. ~40ft or the OxTox alarms start going off.
The atmos AI will also drop into the 50% F02 mode when the air pressure drops to zero.
Which is how I ended up taking a dive in 50% mode. Set F02. Had to replace the o-ring.
(which caused the pressure to drop to 0). Then did the dive.
The computer silently reset my F02 back to 50% with no visible indication.
Now I disable the 50% F02 mode.


--- bill