How do you know you're diving 21% Nitrox?

[DandyDon]

I have a Beaver Diver T-shirt from Key Largo I think.

 

[SCUBA482]

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[/COLOR]CO—it's carbon monoxide you're worried about.
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Yes, thats what i meant but messed up on typing..thanks for the typo correction.

 

[redacted]

I have a Beaver Diver T-shirt from Key Largo I think.

Did you buy it or earn it?

 

[DiveNav]

....If your diving a 21% mix ( Air ) ..... Do you test your mix?

If I am diving locally .... NO. Because .... I might get to 60ft if I use a shovel

If I go to the island (Catalina .... deeper dives), it depends on which dive store filled my tanks (some dive stores do NOT have Nitrox capabilities).

When I am on the dive boat .... No .... unless I see something weird going on :shocked2:

In general. I think this is a good question.

Alberto (aka eDiver)

 

[Dr. Lecter]

Yes, that is the question: What is it?

Yes, you need to verify that it is not 100%, 99%, 98%...50%...40%...32%...28%.....

Don't assume it is 21%!

You will only know by testing the tank.

Right, which is why all OW students are taught that they need to analyze the O2 % of every tank they buy.

Oh, wait...

 

[dwhthediver]

I fill my own tanks at the shop where I teach, all my tanks save one are O2 clean, and therefore filled at the Nitrox mixing station, anything going through the filters gets logged, even air, and anything logged, gets analyzed, so I do analyze all my tanks except the air only tank which is filled on a cascade with no extra oxygen available on it, so it doesn't get analyzed. Beaver, since Nitrox can also be hypoxic mixes, you could argue that 21% is nitrox, but recreational divers are taught "enriched air Nitrox" which by definition excludes hypoxic, and 21%.

 

[Graeme Tolton]

I dont make it a habit of checking o2% of air fills. That being said, most local shops do not bank nitrox. One shop i used to get fills from gave my buddy a fill of 32 in his doubles shortly after they began banking 32. We were loading the tanks back into the truck when the girl working in the shop ran out and told us to check the tanks because she might have given us nitrox.

Now i have a compressor and only pp blend. I only analyze the tanks thst get o2 first or have a partial nitrox fill first. The compressor has an inline co alarm, so checking each tank is pointless.

 

[Splitlip]

But that is not the question, Do you analyze your 21% nitrox tanks?

YES! Always.
The shops I frequent do more nitrox than air. I've seen dozens and dozens of tanks stacked at the fill station with techs feverishly filling them. And now that nitrox wraps seem to be going by the wayside, I can see how a mistake can be made.
I heard a pretty scary story some years ago where an 80 made it on the boat with pure O2.

Ya know, you don't trust the guy filling the tank to give you the plus 21% mixes you ask for and you test them. Why would you not do the same for 21%?

---------- Post added at 07:37 PM ---------- Previous post was at 07:33 PM ----------

Right, which is why all OW students are taught that they need to analyze the O2 % of every tank they buy.

Oh, wait...

I know what you're saying, but if you know enough, why not test.
My daughter is only open water. She doesn't know anything about nitrox or analyzers, but I analyze all her fills.

But then, I am her father.

 

[Graeme Tolton]

Now that i think of it, another buddy came home with a set of doubles full of 21/35 when it was supposed to be 32% i guess the o2 coming out at 20.5 was the tip off.

The bigger hazard there would be getting bent. And being stone cold sober when doing so.

Expensive for the shop if that happens often.

 

[Splitlip]

**** happens. Maybe someday, open water students will learn to analyze their gas. Time was we were not taught to use a bc or octopus or spg in open water.