New to Nitrox - Do I need to buy an O2 Analyzer?

[Aotus]

it appears the discussion has degraded...


OP: if a couple hundred $ is in your diving budget, buy an analyzer. It's better to know, regardless of how rarely you dive, and it seems that the destination shops are the ones where weirdly wrong values are found. If you want to be safest, you should be checking your tanks for CO on those trips too. CO kills. Good luck, have fun. run away from this thread before it turns to incoherent grunts.

Here's some reading for you:
1. http://www.cavediver.net/forum/show...cident-at-Sisteme-Cocodrilo?highlight=brenden
2. http://www.scubaboard.com/forums/ne...-bad-air-originating-tank-not-compressor.html
3. http://www.scubaboard.com/forums/accidents-incidents/413185-fatality-cabo-san-lucas-march-3-a.html
4. http://www.scubaboard.com/forums/ac...e-suspected-near-drowning-virgin-islands.html
5. http://www.scubaboard.com/forums/advanced-scuba-discussions/491634-quality-air-nitrox-issue.html
6. http://www.cavediver.net/forum/showthread.php/19168-Bad-Gas-Incident

 

[KeithG]

it seems that the destination shops are the ones where weirdly wrong values are found.

I disagree with this as a blanket statement - high quality dive destinations have high quality equipment. And spares in case of malfunctions. We frequent high quality dive destinations.

it appears the discussion has degraded... run away from this thread before it turns to incoherent grunts.

Too late!

 

[Lorenzoid]

I disagree with this as a blanket statement - high quality dive destinations have high quality equipment. And spares in case of malfunctions. We frequent high quality dive destinations.

I agree. I can't say I have dived all over the world with a statistically significant sampling of dive resorts and liveaboards, but I have yet to find one where the nitrox analyzer yielded suspicious results. If I do a calibration and my reading is about the same as those that all my fellow divers are getting, what is the likelihood that the results are "weirdly wrong"? I can agree with Aotus' statement about CO, but as far as nitrox analysis is concerned, I'd like to know on what basis he draws that conclusion about "weirdly wrong values."

Also keep in mind that the OP is talking about resorts and liveaboards. In those situations, either there is a divemaster leading the group around who typically resists individuals pushing the NDLs or MODs, or you the diver know better than to push the NDLs or MODs. It's a vacation resort, not an expedition. Sure, if a diver does happen to be at a resort or liveaboard where pushing the limit is likely--maybe Truk lagoon or something--then maybe it's prudent to be extra cautious, but I think most of us who just do vacation diving at resorts and liveaboards can trust that the operation's analyzers yield results that are close enough that we won't get bent or exceed a MOD.

 

[Aotus]

I don't know if it's my comfort level in the water or that I now only dive 32%, but I used to feel wiped out after most dives, and now I'm happy and ready for lunch and another dive. there seems to be disagreement even among agencies about whether EANX influences how you feel - PADI says it doesn't, I think it's PSAI or maybe IANTD that says it does. If it works for you, great! Who cares if it's a physiological outcome of the different mix or a placebo, either way you're having more fun (and get more NDL time and shorter SIs).

DAN is on the side of "doesn't reduce fatigue" : Alert Diver | Air, Nitrox and Fatigue

 

[KeithG]

DAN is on the side of "doesn't reduce fatigue" : Alert Diver | Air, Nitrox and Fatigue

To the best of my knowledge there is no scientific evidence of nitrox reducing fatigue. Just lots of lay people shouting "it werks!".

Kind of like the proponents of Oil or Oregano claiming it cures all ills. Zero scientific evidence. Just lots of marketing BS by the people selling the snake oil.

So let's stick to known, proven facts. Nitrox does have some scientifically proven & verifiable benefits. And is useful is certain situations. Decreased fatigue is not one of them.

 

[Aotus]

What's been determined, is that there is no clear (statistically significant) benefit. Not that there is no benefit. That is the limited inference that can be gleaned from the research at this time. The possibility that it may have some effect is confounded by the (potentially very powerful) placebo effect. Rather than stomping my foot and saying that nitrox has no effect, I say that if you feel better, good for you, but the source of your feeling is unclear.

 

[dmoore19]

Alert Diver | Air, Nitrox and Fatigue

Are there any reliable data to support claims about nitrox causing less postdive tiredness than air?

Harris: No. Three articles in the peer-reviewed literature (see the first three in the references sidebar) contribute evidence to the nitrox and fatigue question, but I am not convinced that the size and power of any of them have addressed the problem comprehensively.

Pollock: The data supporting these claims are not compelling. This is not surprising since PO₂ increases substantially in response to depth alone. However, there is no reason to argue over whether a person feels less fatigued. Research has shown that the placebo effect has physiological impact, so let the diver enjoy the sense. The important thing is for divers to stay within the PO₂ limits to avoid oxygen toxicity.

 

[jdg]

I notice no diff. Between air or nitrox for diving. What I do notice as someone with allergies, As soon as I start breathing well filtered air my breathing clears right up underwater. What I do gain with my steel tanks 110's with 3000lbs with nitrox a lot more diving time. Do I come up feeling better on nitrox? Bla, no diff.

 

[dmoore19]

With the article from Dan. there are people who don't think think the studies are comprehensive. There is, as stated, benefit even if it is a placebo effect. One of them even says "The data supporting these claims are not compelling. This is not surprising since PO₂ increases substantially in response to depth alone. However, there is no reason to argue over whether a person feels less fatigued"
te th
It depends on what expect to gain from using Nitrox, If you don't feel as fatigued then appreciate the benefit, no reason to condemn it.

 

[KeithG]

What's been determined, is that there is no clear (statistically significant) benefit. Not that there is no benefit. That is the limited inference that can be gleaned from the research at this time. The possibility that it may have some effect is confounded by the (potentially very powerful) placebo effect. Rather than stomping my foot and saying that nitrox has no effect, I say that if you feel better, good for you, but the source of your feeling is unclear.

I fully agree with the concept of "placebo effect".

i believe the placebo effect has been proven to be real. The human mind is a very powerful thing. But it has its limits. A placebo pill will not regrow a missing leg.

If someone is convinced that some item has an effect, then it will have "at least" the full effect that our mind is capable of. Both positive and negative. More energetic? Things taste better? My elbow hurts less? I am getting fatter? All of these can be affected by placebo.

So as long as you advocate unharmful activities, have at it. And be happy. But please do not try to make unsupported scientific claims.

For me, I am not paying the surcharge for Nitrox as it does not affect my bottom time.