Can someone explain the F02 settings on Atmos Elite?

[jfoster33702]

I am diving AIR, and it is set to AIR - but there is another F02 setting under the "SET 2" menu that is set to ON and 50% as default. I dont quite understand the logic behind this and what I 'should' have this set to.

Thanks
Jeff

 

[HowardE]

21

 

[jfoster33702]

In one setting, it allows you to pick the percentage, or AIR. I picked AIR. There is another setting, deeper in, that also says F02 though.

I understand why you say 21 - but I think that, to understand my question, the answer is going to have to come from someone who owns this computer?
http://www.diveaeris.com/PDF/12-7156-r01.pdf
See page 20 and 21. And 31

Thanks!
Jeff

 

[95VROOM]

You might want to ask Doug in the Aeris sub-forum under manufacturer's Q&A.

My understanding is that this is a safety option to where, if this option is set to ON, the BC will default to a very restrictive FO2 setting of 50% unless you enter something different.

If the computer cycles off after diving, which takes a long time, it will reset to air. If you make more than one dive and the computer remains on, and you have set an FO2 other than air, you have to to either remember to reset your FO2 for the follow-on dive, or if this option is set, the computer will assume 50%

If you have this option set to ON, the unit will assume 50% unless you tell it different. If you set this option to OFF, the last entered FO2 will be used on a subsequent dive. So, it protects you if it is set to ON by being very conservative if you forget to resety you FO2 value. If you set this to OFF it is up to you to reset the FO2 if you are changing mixes. If you forget, you may have a incorrect readouts and that can be dangerous if you are diving a different FO2 than the computer is set to.

 

[HowardE]

In one setting, it allows you to pick the percentage, or AIR. I picked AIR. There is another setting, deeper in, that also says F02 though.

I understand why you say 21 - but I think that, to understand my question, the answer is going to have to come from someone who owns this computer?
http://www.diveaeris.com/PDF/12-7156-r01.pdf
See page 20 and 21. And 31

Thanks!
Jeff

My wife has the Atmos 2. Once you change the nitrox percentage from Air at all... you need to set your mix on every dive. Otherwise, the computer defaults to 50% which will send the computer into a PPO2 Alert if you exceed the MOD for PPO2 which is set on the computer as well. I believe the default for that is 1.4 ppo2. I don't know WHY they do that...

 

[letterboy]

on my Elite the set 2 setting is for your PO2 which sets how much partial praessure of O2 u want in your body. . . In set 1 once you change from air you cannot change back to air for 24 hrs after your last nitrox dive. In addition it is a saftey feature that once you complete your dive on nitrox the computer sets the FO2 to 50% this is to ensure that if you have switched cylinders and it is a different mix say a 36% versus 28% on your first dive, you don't get O2 Toxicity.

 

[Tsalagi]

I think he may be referring to the post dive default setting. I'm not sure without looking at the manual but you can enable/disable the 'default to 50' for the postdive. The thinking behind it is if you surface for more than 10 mins the computer defaults as a safety measure in case your swapping tanks and O2 percentages. If you have the documentation it explains it pretty well. You should also be able to dload it off the mfr website, if not the oceanic website has the docs available online and it should be very similar.

 

[miked]

You might want to ask Doug in the Aeris sub-forum under manufacturer's Q&A.

My understanding is that this is a safety option to where, if this option is set to ON, the BC will default to a very restrictive FO2 setting of 50% unless you enter something different.

If the computer cycles off after diving, which takes a long time, it will reset to air. If you make more than one dive and the computer remains on, and you have set an FO2 other than air, you have to to either remember to reset your FO2 for the follow-on dive, or if this option is set, the computer will assume 50%

If you have this option set to ON, the unit will assume 50% unless you tell it different. If you set this option to OFF, the last entered FO2 will be used on a subsequent dive. So, it protects you if it is set to ON by being very conservative if you forget to resety you FO2 value. If you set this to OFF it is up to you to reset the FO2 if you are changing mixes. If you forget, you may have a incorrect readouts and that can be dangerous if you are diving a different FO2 than the computer is set to.

Hi Jfoster,

I have an Oceanic Versapro-IIRC very similar in some functions to the Aeris- and what 95vroom says is correct.
I'd also check with Doug, to get the "official" word.
Good luck,
Mike

 

[newportscuba]

My wife has the Atmos 2. Once you change the nitrox percentage from Air at all... you need to set your mix on every dive. Otherwise, the computer defaults to 50% which will send the computer into a PPO2 Alert if you exceed the MOD for PPO2 which is set on the computer as well. I believe the default for that is 1.4 ppo2. I don't know WHY they do that...

Almost all Nitrox computer have a default similar to this.
Exactly as howarde said but the behind the scenes calc for the computer is that the O2 defaults to 50% and for nitrogen tracking it defaults to 79% (yes and impossible mix to have) but what it does is give you the worse case scenario for both gasses to keep a diver from diving too deep and toxing as well as giving you worse case nitrogen tracking to keep the diver from getting bent.

all you need to do is remember to set your mix before your next dive even if it is just air.
Another note is to check out your computers manual.
Some computers you can set your next mix and lock it in until the dive is made.
and some are on a timer where if you set your mix and aren't doing the dive with in X minutes it we default back to the above stated worse case scenario settings.

I used to dive a genesis nitrox resource that if you weren't on the dive within 10 minutes of setting your mix it would shift back to the above default on me.

Check your manual and see what it says.

 

[jfoster33702]

Thanks for the info guys. From what I am gathering, this setting ONLY becomes active if the F02 on the first setting is set to anything but AIR/21? So if I used Nitrox, and set it to say.. 28%, then the other default settings would apply after each dive - for my own safety.

Thanks again!
Jeff