Testing your breathing Gases Prior to Diving

[D. Martin]

Sir it only takes one bad tank below 19% or over36% depending on depth of dive to create a fatality. And as for the fact of analyzing air it is so simple that anyone can be trained in how to do it in a manner of minutes.

 

[PfcAJ]

If your dive shop has the capability of filling the tank with something other than air, assume it was filled with something other than air till proven otherwise.

 

[fnfalman]

Sorry , I could care less if I convince you or not Its your life.
Hopefully diver reading this topic would see the reason why every tank has to be analyzed.
The argument of OW divers not even knowing how to do it is irrelevant. It just proves OW program needs to be improved.

So when I'm on a dive boat that doesn't have Nitrox capability, I should analyze to make sure that I have air instead of some unknown mix of Nitrox?

Yeah, it's my life and I don't care what you think of it, but I think that I'm not going to analyze my tank fills during those trips.

 

[Gren]

So when I'm on a dive boat that doesn't have Nitrox capability, I should analyze to make sure that I have air instead of some unknown mix of Nitrox?

Yeah, it's my life and I don't care what you think of it, but I think that I'm not going to analyze my tank fills during those trips.

Does that boat rent tanks out? Is it possible that the last user filled it with something else? There is a current thread on making a cheap fill whip so I'd argue that anything is possible.

It isn't that difficult or time consuming.

Sent from my Nexus 7 using Tapatalk 4

 

[chrpai]

There is a difference between complacency and paranoia.

 

[elan]

We should look at this from the risk vs. cost. The risk is that one can get injured or die due do using a wrong mix. The cost is 100-300 USD upfront , 100 for a new sensor every few years and couple of minutes before the dive one sharpie every year or so and masking tape for stickers. With that cost I just cannot see reasons what could stop from investing into one of these devices.
Even if we speak air filling only which steel tanks it is still possible that air can get hypoxic after sitting in the tanks for a while.

 

[Altamira]

There's no helium at my shop.

---------- Post added August 11th, 2013 at 07:20 AM ----------

Fwiw an ow diver wouldn't even know how to analyze a tank. They haven't been introduced to the concept yet.

Oh really! That is a broad and highly inaccurate assertion, especially considering you do not have to be anything other than OW to be EANX certified.

 

[Jim Lapenta]

in ye olde days it wasnt a problem !
now a days even if you dive AIR you should still check it !!!!
the one thing i just dont understand if you are certified to dive EANx and its availible and benificial to extend your dives then why the devil would you not use it!!!!! and it cant be costs!!!! = safety thats fall economy!!! for the price of a couple of cups of coffee just stupid
imho

For me it's due to the fact that nitrox offers zero benefits to the majority of dives I do locally. Even the few deep dives I have done this season don't warrant it. It's just as easy to incur a little deco. Nitrox is not a magic bullet. It's a tool. One that on dives less than fifty feet is just not called for. Especially when I am only doing two or three a day.

Sent from my DROID X2 using Tapatalk 2

 

[chrpai]

Oh really! That is a broad and highly inaccurate assertion, especially considering you do not have to be anything other than OW to be EANX certified.

Give me a break. That's an EANx diver not an OW diver.

 

[Crowley]

This discussion already seems to be getting a little "grumpy" and based on personal opinion rather than factual information...

Some points: When it comes to Enriched air or other nitrox blend - gas analysis is absolutely mandatory. Even if it's mixed by a membrane filter system (which removes nitrogen prior to compression), there is always a remote possibility that the mix is not accurate. If it's mixed by a partial pressure blending system which involves pumping pure O2 and then topping up with air then there is an inherent risk due to the process by which the gas is mixed. A third system involves "injection" of oxygen into the air supply prior to compression and for sure it would be possible to fill an air tank with the wrong percentage of enriched air, but there would have to be several failures of observation along the way, not some instantaneous flick of an un-noticeable switch or twist of the wrong valve.

For simple air fills, the risk of any problem is miniscule, although as Scubaboard knows all too well, it does happen from time to time due to poor compressor maintenance. This is most likely to occur in small operations in countries with poor or non-existent regulation. If in doubt, ask to see compressor logs and maintenance schedules. This is covered in most basic courses that I'm aware of.

For more complicated filling, usually for technical gas mixtures involving helium, the mixing system is almost entirely independent of the main compressor - it has to be. The gas is blended and then "topped up" with compressed air. The risk of a hypoxic air fill from a company that is mixing technical gas mixtures is pretty much non-existant because again, there would have to be a number of failures along the way, in what is a fairly time-consuming process, by somebody who should have had a fair bit of training before even attempting it. And then there's blender and user helium/oxygen analysis which is also mandatory.

I know somebody (well, a friend of a friend) who got complacent and failed to analyse a gas mixture for a tec dive and sadly didn't survive. For anything "mixed" - please analyse. For air fills, really, don't worry, unless you are concerned about CO poisoning which is extremely rare, but sadly does happen.

For the steel tank thing - yes, it's possible for a tank to "rust" and reduce the O2 content. There's are some very simple ways of preventing that problem!!

Safe diving all,

C.