Nitrox Blending - Single Tank

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I'm not questioning DCS. I'm questioning O2 toxicity.

Oh, I didn't mean to imply that it had anything to do with 24 hour clock O2 tox. Most of the discussion in my nitrox class was on how difficult it is to get hit that way.
 
Oh, I didn't mean to imply that it had anything to do with 24 hour clock O2 tox. Most of the discussion in my nitrox class was on how difficult it is to get hit that way.
You didn't imply anything about O2 toxicity. But posts #14 and 15, to which my comments in post #17 were directed, were specifically about O2 toxicity.
 
You didn't imply anything about O2 toxicity. But posts #14 and 15, to which my comments in post #17 were directed, were specifically about O2 toxicity.
Sorry, I see now. I was trying to catch up and read through those posts too quickly.
 
Sorry, I see now. I was trying to catch up and read through those posts too quickly.
LOL. Lots of posts, lots of noise, very little signal.
 
Your math is close enough, but you're really splitting hairs here. 23% isn't any appreciable difference in NDL, especially as a repetitive dive. 30 seconds worth of water bath isn't going to make an appreciable difference. Set your computer to your mix for your first dive, then just set it to air for the subsequent two. Or just leave it on air for all three and enjoy the added conservatism on your first dive. And analyze your tanks.

There's no need to overthink this.
 
This is so over thought. At 23% your mod is around 167 few and the NDL difference is negligible. Set on air after the Nitrox dive and don’t bother with any math. But good for you for understanding how the math would be done.
 
1+ for setting the computer at air after the first dive. This is a KISS moment, the extra work setting the computer to calculate 2% of O2 seem like a waste of time. Nothing wrong with measuring your gas on the subsequent tanks, but the extra work on resetting your computer to be precise is a waste.
 
I'd suggest that being precise with breathing gas management is an excellent habit to get into, and to maintain. Particularly, but not only if, a diver is entertaining any thoughts of technical training in their future.
 
1+ for setting the computer at air after the first dive. This is a KISS moment, the extra work setting the computer to calculate 2% of O2 seem like a waste of time. Nothing wrong with measuring your gas on the subsequent tanks, but the extra work on resetting your computer to be precise is a waste.
Depending on the computer it could actually be a very short process to set it and be more accurate. Certainly would be on my Perdix (I reckon it would take only a few seconds more than setting it to air) but it would be a different task on my Cressi Giotto.

It might not make that much of a real world difference but if it only involves minimal effort, then why not?
 
Depending on the computer it could actually be a very short process to set it and be more accurate. Certainly would be on my Perdix (I reckon it would take only a few seconds more than setting it to air) but it would be a different task on my Cressi Giotto.

It might not make that much of a real world difference but if it only involves minimal effort, then why not?
The original post (to which I was addressing my reply) was not measuring his gas with a meter and doing the calculations long hand. On the first tank he *knew* (or at least claimed to know) it was EAN 32. On second dive he *calculated* it was EAN 23. Reguardless of how easy it would be to set the computer, he only *thinks* he knows the gas mix. Setting it at regular air incurs no negative risks and increases his margin of safety (although it is negligible).

I know the limits of what I will accomplish math wise on boat in the sun. The easiest calculation to make is none at all, so calling it air and avoiding the math seems like best solution.
 

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