Checking Nitrox Tanks

Anyone who dives nitrox knows that sometimes checking tanks individually with an oxygen analyzer can be a PITA if many divers are using it and they are all going diving at the same time.

I once asked a dive instructor if checking the tanks individually was really necesary. He answered "if the mix is wrong, it can kill you, do you really want to depend on someone else?" My reply was "we got here on a jet aircraft, I depended on the pilot and if he screwed up we would all be dead." The dive instructor did not like that.

Anyway, I am thinking that nitrox has been around enough to be a mainstream commodity. I don't know how all the possible ways of mixing it work, but it seems that there ought to be some automated method that would reliably produce a constant source of EAN 32. Gas that came off such a system would go into specially marked tanks, say with a blue and white EAN 32/MOD 110 label. If that shop did fills that varied from EAN 32 those fills would have to be done in a different area in tanks using the traditional green and yellow nitrox label. EAN 32 tanks with the blue and white label would not be individually checked. Nitrox in tanks with the green and yellow label would be individually checked as nitrox is today.

I realize that someone could intentionally mess with a tank and put something other than EAN 32 in a tank that is supposed to have EAN 32 in it. But that is like putting poison in Tylenol, and besides, someone could adulterate an air tank and those are rarely ever checked.

Does anyone think this would work?

leadweight once bubbled...
Anyone who dives nitrox knows that sometimes checking tanks individually with an oxygen analyzer can be a PITA if many divers are using it and they are all going diving at the same time.

I once asked a dive instructor if checking the tanks individually was really necesary. He answered "if the mix is wrong, it can kill you, do you really want to depend on someone else?" My reply was "we got here on a jet aircraft, I depended on the pilot and if he screwed up we would all be dead." The dive instructor did not like that.

Anyway, I am thinking that nitrox has been around enough to be a mainstream commodity. I don't know how all the possible ways of mixing it work, but it seems that there ought to be some automated method that would reliably produce a constant source of EAN 32. Gas that came off such a system would go into specially marked tanks, say with a blue and white EAN 32/MOD 110 label. If that shop did fills that varied from EAN 32 those fills would have to be done in a different area in tanks using the traditional green and yellow nitrox label. EAN 32 tanks with the blue and white label would not be individually checked. Nitrox in tanks with the green and yellow label would be individually checked as nitrox is today.

I realize that someone could intentionally mess with a tank and put something other than EAN 32 in a tank that is supposed to have EAN 32 in it. But that is like putting poison in Tylenol, and besides, someone could adulterate an air tank and those are rarely ever checked.

Does anyone think this would work?

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Why can't we just be responsible adults and make sure we analyze the mix before we dive and avoid all the rigamorale you're describing...

I'm not trying to be a smarty pants, but it seems like this is a very elaborate solution that involves a fair amount of bureaucracy to what should be a very simple and easily solvable problem.

No, I don't think this would work. First of all, mistakes happen. Someone could accidentally fill a Nitrox 32 tank with Nitrox 36. Most of the time this doesn't happen, but it could.

Also, MOD can change significantly just by adding a decimal amount of O2 (i.e. 32.8%). I would want to know this.

Your airplane example is a good one. But if it were up to me, I would fly my own plane! Sometimes, if you want something done right, you have to do it yourself. Also, the captain of the plane you just flew in has a co-pilot which can back him up. Same thing can be said for double checking your EAN mixture. It's just good practice.

Just my two cents.

Actually, I would agree that in a "perfect world" where every dive shop was able to bank and supply standard mixes in enough diversity and quantity, and that tanks were inexpensive enough such that you could devote tanks to specific mixes, the system proposed would be ideal.

Unfortunately, it isn't profitable enough for the dive shops to bank many different mixes, and most people won't be able to have enough tanks to dedicate to specific mixes, so you are going to have mix variations as well as tanks that need to hold different mixes as different dives need, so testing your gas each time is really the only way to go.

jhnsndn once bubbled...
Also, MOD can change significantly just by adding a decimal amount of O2 (i.e. 32.8%). I would want to know this.

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My understanding is that the available analyzers are accurate to within +/- a percent.

Am I understanding you? You want a diveshop to buy some kind of automated system! I can't even pay the rent or property taxes.

You want to fill different mixes in different area? Just how much room do you think we have.

I hope you didn't put too much time into this. LOL

leadweight once bubbled...

Does anyone think this would work?

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I snipped the rest of your idea since it appears everyone has the jist of your post.

However, my answer to your question is that not only don't I think it would work, I think the premise is ridiculous.. I say that without wanting to start a flame war, or sound insulting, but analyzing a tank take seconds, at best a minute.. To trust your life to a dive shop fill person makes absolutely no sense to me at all.. A good friend of mine had a shop owner; a certified trimix diver; and blending technician tox out on him because the very person that blended his own tank, never bothered to analyze it, and put the wrong mix in the tank. You are suggesting a system that sonner or later will fail, it's not a question of IF, but a question of WHEN.. Then WHEN it fails the lawyers will be circling the wagons because once again, we will have removed personal responsibility from the very person who's life stands in the balance.. I normally blend my own tanks and even then I wouldn't get in the water without analyzing it, I certainly wouldn't go to a dive shop in Cayman, for example [ or some other cattle boat operation] and assume that because the tank I'm about to breathe has a "blue" band on it that it meant the 18 year old that blended this one of a hundred tanks, actually got it right.. Even if you were to rely on some yet-to-be-invented technology why in the world wouldn't you spend the 30 seconds or so, to analyze your breathing mixture????

This experiment is frought with problems and will ultimately lead to a fatality and in my view I hope it never takes off..

Diving is about personal responsibility, diving elevated oxygen mixes extends the level of personal responsibility, and in my view, any attempt to abdicate that responsibilty in favor of some ad hoc shifting of the burden is doomed from the start..

Later

I think some of you are reading a bit too much into this. The system does not have to be fully automatic. The idea is to keep the quality control upstream, where it should be in the first place, IMO. A separate location could be no more than a separate bank of fill whips.

I realize that many of you view nitrox as a custom mixed item where the the diver might select something less than EAN 32 for a dive where a deeper MOD is needed or something more as a deco or rebreather mix. Not all locations supplying nitrox work that way. At a resort or on a boat it will often be EAN 32 or AIR and that is it.

A dive shop would not have to adopt this standardized EAN 32 proceedure if it did not want to. They would just keep doing things like they do now and all EAN tanks are treated as unique and get analyzed whether or not they contain EAN 32.

Frankly, I believe that at locations that do only EAN 32 now this would cost less as it eliminates the staff time that goes into watching the divers analyze tanks. Standardization usually results in lower costs. I agree it is unlikely that many dive shops would want to do it both ways and I agree it would cost more than it does now to do it both ways. However, they would have the option to do it both ways if they believed it would be profitable.

Meanwhile, I did not spend that much time on the idea and don't think that should concern anyone. And if you are LOL then thank me, because laughter is the best medicine.

I don't think you are flaming me. Ideally analyzing a tank should take seconds. I have seen it take over 30 minutes to analyze all 20 tanks for 10 divers on a single boat.

Some people take the personal responsibility thing to the extent that they insist on doing their own regulator rebuilds. I let the tech do mine.

leadweight once bubbled...
I don't think you are flaming me. Ideally analyzing a tank should take seconds. I have seen it take over 30 minutes to analyze all 20 tanks for 10 divers on a single boat.

Some people take the personal responsibility thing to the extent that they insist on doing their own regulator rebuilds. I let the tech do mine.

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The answer is more analyzers. hehe but I do my own regs too.