PO2 dive computer warning

[topher10]

Yea, sorry. I had typos and not (I don't think) math issues. So I meant to write PO2 of 1.2 and 1.4 (not 1.02 and 1.04). My bad there and sorry for the confusion. I could edit the first post but probably should just leave it now to avoid further confusion. I am actually not doing math in this case because I have a pre-printed table with PO2 values for 32 and 36 at common depths, and so I just looked up the depths for 1.2 and 1.4 with 36% on my table.

The computer is an Aeris A300, which is an older and cheap computer that does everything I need. However, in NORM mode it has a series of built-in alarms related to NDL, PO2, safety stop, etc. Most of these alarms I actually like. I have not run into the PO2 alarms before because of only a few nitrox dives, but it gives a warning at 1.2 and another alarm at 1.4. I cannot turn this off in NORM, but I could swap to TECH and edit these myself. I am hesitant to do so just due to my lack of experience.

The goal of my post was to get a feel for whether keeping above PO2 of 1.2 made any sense or if that was being hyper-conservative. My general feeling is that its being hyper-conservative. For example, there is nothing uniquely dangerous about a 45-minute dive on 36% at 80 ft, especially if that is the first of only 2 dives that day, with the next dive being shallower. I think if I was doing 5 dives in a day, then maybe I would be more conservative. But I would certainly welcome other options.

 

[caruso]

Yes PO2 1.2 is ultraconservative as I said I use and recommend 1.6 for the reasons stated above. Changing PO2 settings manually is no more difficult than setting your alarm clock. Be brave, read the manual and customize your dive experience. And for the benefit of your fellow divers please silence the audible alarms for all but the most dire emergencies. Exceeding PO2 1.3 isn't one of them.

 

[tursiops]

Just turn off the alarm for PPO2 at 1.2. If that requires TECH mode, so be it.

 

[JohnnyC]

Edit everything in your first post. It makes you look like either something is wrong with your computer or you don't have an understanding about the subject. Leaving the typos isn't doing you any favors and muddies the water.

 

[BoltSnap]

Yea, sorry. I had typos and not (I don't think) math issues. So I meant to write PO2 of 1.2 and 1.4 (not 1.02 and 1.04). My bad there and sorry for the confusion. I could edit the first post but probably should just leave it now to avoid further confusion.

Leaving it as it is now creates more confusion and shows that you don't know what you are talking about. I highly suggest that you correct the mistakes, no reason to leave them as is at all. You should do it before the SB system locks you out of being able to edit your OP.

 

[topher10]

Ok. Fixed. I am fine with the thread being deleted at this point, since I have my answer.

 

[JohnnyC]

I think it’s a good thread, especially for new divers who may have a similar question. I think a lot of new divers are in the same boat, trying to reconcile the manufacturers decisions and assumptions with their own training, which may or may not have been thorough enough to really impart understanding.

If you want to delete the thread, you can always report it and ask a mod to get rid of it, but I think it’s worthwhile to keep around, and I think you did a good job of highlighting an issue and the thought processes of a new diver trying to decide what course of action they should take.

 

[caruso]

Ok. Fixed. I am fine with the thread being deleted at this point, since I have my answer.

You edited your first post but you didn't leave some sort of comment to the effect of "Post edited to change 1.02 to 1.2" or something like that. It would make it easier for others to understand what all the replies are about.

You got your answer but this forum isn't here just for you, it's for anyone else that might have a similar question. That's what these forums are all about, the sharing and expanding of knowledge to the benefit of all divers, not just individuals.

 

[scubadada]

I have been diving Oceanic computers since 2002. I set the pO2 at 1.6, the warning alarm goes off at 1.4.

 

[davehicks]

As a rebreather dive I often aim to be at a 1.4 ppo2 and hold it for an hour or so. Dipping to 1.6 for a minute here and there is NO PROBLEM. You have nothing to be concerned about as long as you are aware of the situation and don't ignore it for an extended period. You were aware, so keep up the good work!