Systematic use of oxygen analyzers by advanced divers ? [Poll].

[Satrekker]

I verify O2 and CO with an analyzer on almost every tank. O2 always.

 

[boulderjohn]

unless you self fill, or deal with a shop that only does air,

Here in Colorado and I imagine in many other states with no real access to deeper recreational dives, only a couple of shops have the ability to mix nitrox. The shops I use the most only blend nitrox when I do the partial pressure blending myself, I use my own tanks for almost all diving, and I mostly do my own filling. I therefore do know when I am getting only air, but that is a very rare occasion.

When I am doing recreational dives on vacation and renting tanks, I pretty much always use nitrox and so always analyze.

 

[DanielRJones]

So, what if a customer rents an "air" tank and then fills with a high EAN mix at another shop or boat? Do they test/drain all returned tanks? Are they testing the filled "air" tanks"

This is the weakness in the labeling system that is impossible to enforce 100% of the time. Overconfidence in a certain shops process, can lead you to be complacent.

Now, fortunately you are probably not in danger most of the time. Even if you accidentally get a ~31% fill and stay in recreational dive limits. ...but are you sure? What if some traveling diver rents a tank and blends up a 50% deco bottle in his hotel room? Will your shop catch that when the tank comes back still having 2600psi of 50% in it?

Since they are my tanks and not rentals then i would be pretty pissed if somone had mixed a 50% in their bedroom with it. They also do not rent tanks.

 

[Caveeagle]

I figure there's probably about the same chance that I'm going to get a bad air fill (CO or have someone accidentally fill it with nitrox without noticing) as there is that my dive computer is suddenly going to malfunction and tell me I'm at 100 ft when I'm actually at 150' (or one of a thousand other things that could go wrong regarding any given dive). Either error could be quite dangerous, but at some point you have to assume things work properly or you'll never be able to go enjoy a dive. I'm a recreational diver and I'm going to go have fun diving.

Not sure is your statistical risk assessment holds water, but I get your point.

I would counter, that you can have MORE fun when you confirm your tank has a nice 32% EAN mix, and you get more bottom time, and often feel better post dive!

But like I said in an earlier post, I'd you are diving in recreational limits, <100', your risks of o2 tox are extremely low. Dive away! I would not go to 130' or beyond unless I was completely sure of what gas was in my tanks,

 

[lv2dive]

I’m just not sure what you are trying to learn from this poll. Most divers on ScubaBoard are going to say they always test their gas. Period. But that really doesn’t tell you a thing. Because regardless of what this poll says, I can tell you that the majority of (nitrox) divers IRL do not test except when required by shop (when picking up tanks, analyze and fill out dive log) or the operator (on a liveaboard, for example).

I’ve included just two (of many) of my experiences below:
When I was diving Nitrox at a big name recreational op in the Bahamas, the tanks came out with a sticker on them that had the percentage of oxygen only. No date, no initials. I asked the deckhand if I could analyze the tanks (I had not brought my analyzer as it was a family trip and I was just diving recreationally a couple days). The deckhand explained to me that I did not need to analyze the tanks because they had analyzed them for me. I explain to him that I was breathing the gas so I wanted to verify the oxygen content. You would have thought I was asking to start up the compressor and fill my own tanks! Eventually, they brought the shop analyzer out and analyzed the tanks with me watching. (Point - obviously my request was atypical)

On a group trip to Indonesia, again, tanks came out with stickers with O2 percentage and nothing else. This time when I asked, however, they were happy to let me analyze my tanks, on a daily basis. However, the group leader (a DM) basically chastised me for wanting to analyze my tanks. Her reasoning? That the Nitrox was banked - so the tanks had to be right!

Well, I could always try to ask PADI to send me the contact information of a sample of 100,000 randomly selected divers from their database, but somehow I have the intuition that this information will probably not be readily accessible to me..

 

[lv2dive]

You may want to adjust your logic - I mean that sincerely. I personally have gotten hot gas fills and know multiple people who’ve gotten bad (CO) tanks. Computer failures, esp *during* a dive, are MUCH less frequent. I’ve known one person’s computer that was off by a few feet, that’s it. And one person whose computer was reading a couple hundred feet on the surface, obviously they did not take that computer in the water with them.

I figure there's probably about the same chance that I'm going to get a bad air fill (CO or have someone accidentally fill it with nitrox without noticing) as there is that my dive computer is suddenly going to malfunction and tell me I'm at 100 ft when I'm actually at 150' (or one of a thousand other things that could go wrong regarding any given dive). Either error could be quite dangerous, but at some point you have to assume things work properly or you'll never be able to go enjoy a dive. I'm a recreational diver and I'm going to go have fun diving.

 

[jlcnuke]

You may want to adjust your logic - I mean that sincerely. I personally have gotten hot gas fills and know multiple people who’ve gotten bad (CO) tanks. Computer failures, esp *during* a dive, are MUCH less frequent. I’ve known one person’s computer that was off by a few feet, that’s it. And one person whose computer was reading a couple hundred feet on the surface, obviously they did not take that computer in the water with them.

Out of the millions of tanks filled with air around the world each year, what percentage do you think are accidentally filled with nitrox with no nitrox labeling etc on the tank? Serious question, because the overwhelming majority of divers out there have never analyzed a tank in their lives and I've seen zero dive shops that analyze each of their air fills to ensure they are actually air before giving them to those divers who are not going to analyze their tank. Despite all that "no checking air fills at all" I've yet to hear any statistics suggesting to me that all these people are taking huge risks because of the prevalence of this problem you've apparently seen. Even DAN doesn't seem to suggest we should check air fills for excess O2 (though they do recommend checking for CO or unusual odor/taste).

 

[lv2dive]

I can’t tell if you are joking l/trying to be funny about contacting PADI or trying to make a point I’m missing. With all of the answers you have received, why is this even a question?

Educated divers always analyze their gas. And no offense meant to anyone on this thread, but educated divers who’ve been around a while, always analyze ALL their gas, including air. @Caveeagle brought up that very valid point. There was fatality here in NFL a few years ago where the diver was diving air (he thought) and refused to analyze it. Yes, refused, buddies suggested it to him. But he was adamant it was air and he didn’t need to analyze. 100% oxygen does not work so well at 70, 80, 90 feet and the inevitable occurred.

Gas analysis is super quick and considering what’s at stake, I take a hard line for myself and buddies.

Well, I could always try to ask PADI to send me the contact information of a sample of 100,000 randomly selected divers from their database, but somehow I have the intuition that this information will probably not be readily accessible to me..

 

[npole]

If it's EAN21 you normally don't, if it's EAN>21 you must. This standard not optional, it's like asking: "do you wear a mask while doing scuba diving?" ...

Tha above is about the o2 percentage. The quality of the air/blend and the presence of carbon monoxide (that causes most incidents) is another matter, but I don't think that what you was asking.

 

[BazzaB]

I like statistics, but you cannot be a little dead