POLL, Nitrox tank use and analyze

[Jim Lapenta]

I also did not own an analyzer for the first few years I was certed for nitrox. But every shop I used had one. And if it was one I had not seen before I asked them to show me how to use it and then did the analysis myself. Was the way I was trained and see no reason to do otherwise. Those who choose not to analyze every tank and trust the shop and blender have no one to blame but themselves if they tox. Frankly I would not use a place that did not require me to personally analyze the mix.

 

[Mossman]

I picked up four tanks at a Florida dive shop for my buddy and I prior to diving the Spiegel Grove, 2 120s for me, 2 100s for my buddy, which were supposed to be filled with 28% for our first dive to the bottom (140') and 35% for our second dive to 90'. The guy was locking up the shop when we arrived to pick up the tanks and was in too much of a hurry to get home to analyze them for us there. Fortunately I had brought an analyzer on the trip and we checked the tanks before we got on the boat. Sure enough, the labels on the 100s were switched. My buddy would have dove the 35% to 140' had I not been able to analyze the tanks and we decided to trust the shop's labels. Fortunately we realized the simple mistake, saving my buddy her life, and saving the shop from a huge wrongful death lawsuit.

However, in order to cut weight below 50 lbs in our bags, I stopped bringing the analyzer on dive trips where I'd be able to use the dive op's. That's served me well in most cases, with two exceptions. On a liveaboard at Cocos Island, the tanks were filled on the skiffs. The boat crew insisted on doing the analyzing because they didn't want passengers getting on and off the skiffs when we weren't diving. It wasn't a very reassuring system, as the analyzing crew would write the fO2s of the various tanks on the skiff on his hand, then tell us our numbers when he got back on the main boat, occasionally seeming to confuse them. Since the numbers were all in the 30-32% range, we simply set our computers to 30% to be conservative. There are other reasons why I won't be diving on that boat again.

Most recently, in Cozumel, I was surprised to find that the boat picking us up at our hotel did not have an analyzer aboard. The owner/operator assured me that he double-checked the numbers from the place where he picks up the tanks (dive shops in Cozumel don't fill their own) and I made the decision to trust him (he had a nice face). I had a few pangs of worry, but figured that if he had lied and I died as a result, he wouldn't be getting a very big tip from me. He said he normally doesn't bring the analyzer on the boat to keep it from the elements, but if I requested it, he would bring it the next time. Just in case, the next time I go to Cozumel where I plan to dive with the same operator, I'll probably lug my own analyzer along.

 

[gmanstan]

I've never gotten a fill where I was not required to test ,note MOD & sign. Boat or shop.

 

[Splitlip]

Always analyze.
I even analyze my daughter's air fills. Too easy IMO for mix ups in shops that have a hundered or more rental tanks backed up the fill station. Especially if they bank.

Those that mix, pump "X" psi 02 then top of with air. We had an incident once where pure 02 ended up in a cylinder on a boat trip. Fortunately, the air diver checked his SPG before splashing. He'd have convulsed and died somewhere around 20 ft.

 

[willembad]

I set the dial on the stick, watch it throughout the fill to keep from blowing up my garage and then check with a second analyser when the tank comes of the whip. Paraniod? Maybe, but I did dive 32% to 160 fsw once and that will NEVER happen again.

 

[Peter_C]

I checked the first one. I don't dive anything but 32% locally, and never dive below 100 feet. I can keep my banked mixes within .4% of 32%, tested on multiple meters. It is continually tested with an O2 analyzer, where I will sometimes turn off the O2 tank and check to make sure the meter reads 20.9%. I own four O2 meters, and occasionally will check the output of the mix as it is pumping. My friends check their fills, as there is always an analyzer sitting there.

When my mixes come from anywhere but my garage, I check them!

 

[randy88k5]

I always test the tanks myself. And, as I recently found out, when you're in a shop that does trimix, use a trimix analyzer.

 

[Heath Sapp]

I always check. I was diving in the keys couple months ago and had nitrox. The shop dive master had several tanks sitting there. I was the only one who asked to test the tank and there was only 3 others out of 19 divers who carried their tanks back up to be tested. I not sure how many divers were diving nitrox. I will always check. My father just got cert. last year. I won't even dive a tank that he checks.

 

[Mizer67]

My vote is a little misleading. I have never dove an untested tank. I have dove a tank that my daughter (who is EANx certified) picked up and analyzed for me. I work 24 hour shifts and we had to be at the dive site right after I got off so there was no time for me to go pick it up. She tested it and marked the tanks for me. I am good friends with everyone at the shop and an EANx certified dive master double checked my daughter's work. Plus my wife is the beneficiary on the life insurance, not my daughter, so I felt pretty good about it.
I would not, however, dive a tank based just on the word of the guy who filled it.

 

[MuddyRubberDuck]

I don't own an analyzer, but I make every shop analyze them in front of me. I was out of town once, and there was only one game in town so, that's where we went. I was already a little pissed about $20 each so this conversation wasn't exactly nice in tone.
Guy: this one has about 2800.
Me: your going to top those off for me right?
Guy: but then I have to analyze them again.
Me: well you were going to analyze them wether you wanted to or not. Might as well give me $10 worth of air for my $20.

Needless to say, we were waiting outside his shop when he opened, so he knew he had us bent over and spread wide. I still don't know if he charges $20 usually or just knew he could stiff us because we were desperate.