Gas testing and sidemount

[TONY CHANEY]

Is it? I found 14/86 to make me huff while exercising in the mountains, but it sure wasn't hypoxic. What references do you have?

Actually, I guess it depends on your definition. Anything <21% is hypoxic by definition. But 19% isn't dangerous. I am dubious 15% is dangerous, either.

None of it is < 21% in that 21% is the same reguardless of pressure but ppO2 is different.

[Scott]

None of it is < 21% in that 21% is the same reguardless of pressure but ppO2 is different.

true with air, like breathing on a 10k mountain, it is still 21%, but a pO2 of less that .21, but in the mixed they were breathing in the tanks, it was actually less than 21% becuase it was more than 79% of other stuff (N2, He).

[Burke]

I think the concern is related more to swimming hard on the surface or just under it to get from, for example, the sten to the anchor line is a strong current on an offshore deep wreck dive. And the other factors can be important. A 14% mix is by itself probably not an issue, but add a middle aged to older diver who is over weight, out of shape and smokes like a chimney and you have a much greater potential for the diver to pass out and have a serious accident.

I got buzzed good once swimming hard for the down line on 15/55. I soon as I realized what was happening, I dove deeper and it immediately cleared. At the time, I was early 40s, in good shape (runner with good lungs), never smoked. I've never heard of any issues with 18/45, but any leaner than that definitely needs to be treated as hypoxic.

[JS1scuba]

6 pages of discussion of whether or not to analzye both SM cylinders that came off the same fill system (but not same whip).

boys and girls this is basic nitrox 101.

You analyze every cylinder you plan to breathe from. You mark it appropriately. If the label comes off you analyze it again.

If you get lazy with gas analysis what else are you getting lazy with ?

Merry Ho Ho

Cheers
JDS

[FW]

6 pages of discussion of whether or not to analzye both SM cylinders that came off the same fill system (but not same whip).

boys and girls this is basic nitrox 101.

You analyze every cylinder you plan to breathe from. You mark it appropriately. If the label comes off you analyze it again.

If you get lazy with gas analysis what else are you getting lazy with ?

Merry Ho Ho

Cheers
JDS

I agree!

[adam0321]

literaly the one time I did not analyze my tanks i got a very mild case of dcs-1. dove air on 32% tables. about two hours later had visual disturbance and headaches. that was literaly the one and only time i did not analyze my tanks. I am religious about it now. but some shops dont have an analyzer readaly availible then get a lil angry when you ask to borrow one to analyze o2. o well maybe santa will be good to me and throw an expedition in my stocking

[JS1scuba]

but some shops dont have an analyzer readaly availible then get a lil angry when you ask to borrow one to analyze o2.

If you are frequenting a dive center that is in the business of selling you breathing gas other than air then they SHOULD have an oxygen and helium analyzer readily available for you to analyze the cylinders they just filled for you. This is standard operating procedure for any professional dive center. (i dont know about the self service places) If they have a policy that they don't provide an analyzer then they should post that and advise customers of that so customers can bring their own unit with them ..... or seek other services.

Oh, for analyzers just visit our site ..

Cheers
JDS

[PfcAJ]

Where is this shop that gets upset if you ask for an analyzer? I've never had that problem...ever...

[PeterVICEG]

Andrew as one autodidact to another your mountain example makes you a bit of a nob. I did the NE Buttress on Mt. Whitney a few years back, no problem. 5.8-5.9 in thin air, I enjoyed the outing. The thing is I had been at over 10,000 ft. for over a week. Had I attempted this climb straight up from sea level I doubt I could have done this. Those who were on the mountain with me who had just walked up the backside trail were puffing and in need of constant rest. They were more like divers who had just switched to a low pO2 but they could huff and puff and lie down any time. And yes they get into trouble all the time up there. When things go sideways they are known to do very strange things, including dying. This while not underwater.

When I get other than air, I check it. Seems simple enough.

Peter

[MORGAN]

When I get other than air, I check it.

Me, too. And when I get air, I check that, too, to make sure that it's not something other than air.

Mike