Any reported cases of Ox Tox between 1.4 and 1.6?

[inquis]

I would still like to see something about "oxygene window is no longer a thing".

To be clear, the window (i.e., lower oxygen partial pressure due to metabolism) exists. It's significance for decompression diving is what is in question. I have never seen that mentioned by current researchers, literature, or technical diver training materials. Obviously, I have not read/seen/heard everything, but at present, it's very conspicuous by its absence.

@passeparici, you said 6m is "better" when on O2. How does the window make it better as you understand it? Honest question, as I grant that I could be missing something.

 

[boulderjohn]

GUE says that in this article but that doesn't settled the matter. Most other researches say otherwise.

Also I would still like to see something about "oxygene window is no longer a thing".

To be honest, I have not heard that the oxygen window is a thing in so long I did not think it had to be discussed. I didn't think anyone still believed in it.

Mark Powell's Deco for Divers correctly pointed out that it violates Dalton's Law more than 15 years ago.

When I was a UTD diver, UTD believed in it fervidly, and I was sent the article on which it was based. I was amazed, because when you come to the part where they make that conclusion, you don't see any reason for it. It is not supported by the evidence leading up to it. It just comes out of nowhere. I argued the point vigorously with UTD owner Andrew Georgitsis. During that time I corresponded privately with Jarrod Jablonski of GUE, and he said that the scientific basis for it was indeed flawed, but they were at that time going to continue with the S-curve ascent because they had been doing it for a long time, and it seemed to work. They later abandoned it.

I was then in a special ratio Deco class with Andrew, and he admitted that the science behind it was indeed flawed, but they, too, were staying with the S-curve for other reasons that I cannot recall. They were still using it when their version was Ratio Deco came out so badly in the Spisni study.

 

[boulderjohn]

@passeparici, you said 6m is "better" when on O2. How does the window make it better as you understand it? Honest question, as I grant that I could be missing something.

The GUE/UTD version was that the higher the PPO2, the faster you off-gassed nitrogen, because the metabolism of the oxygen created an "oxygen vacancy" that created more room (seriously) for the nitrogen to come out. Yes, that is indeed a violation of Dalton's Law.

 

[Nick_Radov]

GUE says that in this article but that doesn't settled the matter. Most other researches say otherwise.

Which researchers?

 

[passeparici]

To be clear, the window (i.e., lower oxygen partial pressure due to metabolism) exists. It's significance for decompression diving is what is in question. I have never seen that mentioned by current researchers, literature, or technical diver training materials. Obviously, I have not read/seen/heard everything, but at present, it's very conspicuous by its absence.

@passeparici, you said 6m is "better" when on O2. How does the window make it better as you understand it? Honest question, as I grant that I could be missing something.

It is already quite difficult to understand as it is quite technical so to explain it ! I sugest you read the links that have been put here to start with but yes, at the end, what I remember for me is that it is for decompression to have a higher ppO2 (1,6 at 6 m for 100 % oxygene). I am not sure it shorter the time (and I think the computer doesn't really take it into account, it seems mine doesn't (Teric)) but it will be a"better" decompression (and that's where it is too difficult for me to explain it). Why we don't really see more things about it : I don't know. It might be because the time is not really changed... I discovered it a while ago (in this forum or another one, I will try to find the link) because I was certain that 3 m was better as it is normally with any decompression and someone said something about oxygen window.

 

[passeparici]

Here is a link and read "deco for divers" they speak about it in it

 

[tursiops]

The attached may be the original article in English as published by GUE in 2004 but no longer on their site, that started this discussion. Johnny E. Brian, Jr., is Eddie Brian, Jr.

 

[lermontov]

I generally dive nitrox for the longer dive times, especially on the 2nd, 3rd, and 4th dive per day. I have very good gas consumption.

what are the physics allowing you to have longer bottom times

 

[scubadada]

what are the physics allowing you to have longer bottom times

Less nitrogen exposure, longer NDLs. Are you asking something else?

 

[inquis]

Here is a link

Yes, that is a French version of the article on the GUE site linked previously. While I agree the tissue partial pressure of O2 is lower than that of the inspired partial pressure, the benefit to deco diving is not given, that I can see. It even states the inert off-gassing is unaffected.