Nitrox Analyzer - How many use one?

[rek_diver]

Also, it seems as if I'm one of those who bubble easily, because if I do two deep-ish, long-ish dives in one day, I want to be in my bunk before 8pm. And nitrox is one of the many tools to reduce that decompression stress.

You are in your bunk by 8 pm because you're getting older and you're not as fit, so the physical exertion of diving takes more out of you. Nothing to do with "decompression stress". I never even heard of that term.

Nitrox has never been proven to reduce so called decompression stress or give more energy or whatever. It does one thing and only one thing- it reduces the amount of Nitrogen absorption in the body when breathing compressed air at depth. Period.

 

[RayfromTX]

There's no exact science because there's just too many variables involved ... not the least of which is your personal physiology and tolerance levels to high partial pressures of O2. It's much like how N2 exposure can lead to DCS in that there's a graduated "gray area" wherein the farther past a certain arbitrary limit you go the higher your risks become of having a bad outcome, based on several other factors. But that doesn't mean you WILL have it. Also, exposure time and differential changes factor into how much risk you're actually taking.

A few weeks back on a solo dive on a wall in Browning Pass I accidentally dropped my camera. I was at a depth of about 80 feet at the time, on a wall with a hard bottom at over 200 feet. I quickly swam down to retrieve my camera, which was sinking, and caught up to it at around 140 feet. As soon as I retrieved it I began my swim back up at a fairly expeditious pace, and slowed down when I got to about 100 feet ... well within the MOD of the EAN32 I was breathing at the time. Yes, I went well below the MOD for the mix I was diving ... but the effects that lead to ox tox are cumulative, and I figured the risks of less than a minute below the "safe" depth were worth taking, considering I was otherwise going to lose about $5000 worth of equipment.

One always needs to factor risk mitigation into any dive ... but it helps to have at least a basic understanding of why PPO2 limits exist, and what it really means if you should need to exceed them in a given circumstance. Of course, it's always better to not have to make that choice ... but sometimes sh!t happens ...

... Bob (Grateful Diver)

When you were in the middle of that event, how are you feeling about it and how was your thought process? We’re you very nervous or only annoyed? How comfortable were you with your decision in the moment? I have no criticism, I only want to know how it felt to you at the time. I suspect I would’ve been cool headed in the moment and a little more worried after the fact.

 

[RayfromTX]

You are in your bunk by 8 pm because you're getting older and you're not as fit, so the physical exertion of diving takes more out of you. Nothing to do with "decompression stress". I never even heard of that term.

Nitrox has never been proven to reduce so called decompression stress or give more energy or whatever. It does one thing and only one thing- it reduces the amount of Nitrogen absorption in the body when breathing compressed air at depth. Period.

This is certainly an old argument that has been had many times before. My dive master in Cozumel and several others that I know of there had learned over time that if they don’t do Nitrox sometimes they will eventually get so worn out from the diving that they will get sick and be unable to continue. One or two days on Nitrox gives them the rest from nitrogen loading that they need to go on. This is when they are diving for 10 or 15 days in a row.

 

[MXGratefulDiver]

When you were in the middle of that event, how are you feeling about it and how was your thought process? We’re you very nervous or only annoyed? How comfortable were you with your decision in the moment? I have no criticism, I only want to know how it felt to you at the time. I suspect I would’ve been cool headed in the moment and a little more worried after the fact.

My only thought was point my fins skyward and kick like hell. Of course I'd hoped to catch up to it sooner than I did, and I didn't think to distract myself with any other thoughts or actions until I had the camera in hand. Then a quick look at my depth and a very quick trip back to a "safer" depth. In point of fact, I made a decision to end the dive and began a slow ascent at that point ... thinking that if anything residual was going to happen I'd have a better chance at a good outcome if I was closer to the surface. The dive was at Seven Tree Island ... one of my all-time favorite dive sites on the planet, and it hurt a bit to not stay down and take advantage of it since I have no idea when, if ever, I'll get back up there. But at the time of the incident all I was thinking about was solving the problem ... which was recovering my camera. I was completely comfortable handling it the way I did ... other than some self-kicking for not noticing that I'd neglected to put the lanyard on my wrist in the first place ...

... Bob (Grateful Diver)

 

[rek_diver]

This is certainly an old argument that has been had many times before. My dive master in Cozumel and several others that I know of there had learned over time that if they don’t do Nitrox sometimes they will eventually get so worn out from the diving that they will get sick and be unable to continue. One or two days on Nitrox gives them the rest from nitrogen loading that they need to go on. This is when they are diving for 10 or 15 days in a row.

Medical definition of the placebo effect

Placebo effect: Also called the placebo response. A remarkable phenomenon in which a placebo -- a fake treatment, an inactive substance like sugar, distilled water, or saline solution -- can sometimes improve a patient's condition simply because the person has the expectation that it will be helpful.

 

[MXGratefulDiver]

You might claim it's all in my head ... well, yes, perhaps ... but if my head tells my body it feels better, what difference does it make?

... Bob (Grateful Diver)

 

[rek_diver]

You might claim it's all in my head ... well, yes, perhaps ... but if my head tells my body it feels better, what difference does it make?

... Bob (Grateful Diver)

Good point.

 

[tomfcrist]

I mix so much gas, that even though I analyze and label after filling, I still analyze before I put tanks in the truck, and again before I dive them. I guess I'm just OCD...I know what is in each tank...but I don't trust my memory(or my analysis tape) as far as I could throw it.

 

[tomfcrist]

What brand and model analyzers are you using and why are you happy / unhappy with your selection?

I use a divesoft trimix analyzer...it can analyze Nitrox, trimix(there is no He sender to replace) use as a multimeter, measure gas purity...etc etc etc. it is also rechargeable.
Works well for me...probably overkill for most divers.

 

[Storker]

You are in your bunk by 8 pm because you're getting older and you're not as fit, so the physical exertion of diving takes more out of you.

The underwater part of scuba diving isn't physically exhausting. Schlepping the gear is what brings on the exertion. And that exertion is the same no matter if the dives are short and shallow, or if they're long and deep. @DevonDiver has a good article about subclinical DCS on his blog, where he also quotes some rather competent hyperbaric scientists. I can recommend it.

Nothing to do with "decompression stress". I never even heard of that term.

Try this, then. Note that the first link that shows up is to alertdiver.com. Ever heard of that publication? Or of DAN, who publishes it?