An in-depth book on trimix diving?

[Rich Keller]

Have to disagree with you there. The OP will be better served with some the civilian publications already listed. "Deco for divers" is a good start.

I do not think ignoring the people who have been doing the actual research and testing for the better part of a century is a good way to go. I have not read any of the other books suggested but I am sure that all of them credit the US Navy Diving Manual as one source for their information.

 

[Subcooled]

I would like to thank you all for some good links and information.

To motivate my quest, I will give an example:

Nitrogen narcosis was discussed on the first diving course that I participated in. A list of signs and symptoms was presented and depths were discussed. This scary new thing puzzled me and so I located some research papers on narcosis (probably twenty or so) and some workshop proceedings etc. Reading and understanding it all took some time but half a year later I had gained some sort of vague understanding of how narcosis affects people, at what depths, and how it intertwines with hypothermia, fear, gloves, and many other disabilitating factors... The truth wasn't simple. The world isn't. I also had the opportunity to experience it twice in a chamber (we did some tests). As a result, nitrogen narcosis is no longer an unfamiliar ghost in the dark. I know some ways how it affects me. I can see it in the experiments we did and I can see it on a video camera. Hence, I feel more confident and I have less irrational fear. As a result I feel safer. This study has also opened my eyes to other factors. The need to pee, for example, can cause more narcosis at 30m than nitrogen

So... this helium is a new "scary thing" because of the inner ear bends, gas switches and counterdiffusion and stuff like that. Reading what little is known about these issues will make me feel better.

When I read a diving manual and it contains unclear chapters then I want to see the sources. E.g. in the GUE book in chapter 5.5.5. on thermal loss it is said that helium mixtures loose heat during its way from the cylinder to the lungs. Well, actually it gains heat from the surrounding water after beeing cooled by pressure drop. Here, for example, I would appreciate some refernces and links.

 

[Diver0001]

Can you recommend me a book or articles related to trimix diving that contain an in-depth, quantitative, properly referenced discussion of breathing, gas switches, hypoxia, carbon monoxide, carbon dioxide, helium, gas density and pressure?

Why are you looking for this?

R..

 

[TSandM]

All breathing gas loses heat from expansion as the first stage reduces the pressure. Especially if water is cold, the gas may not gain much heat at all during its brief trip through the hose. Dry suit inflation gas is COLD when it enters the suit!

I have read all the books above, and a great deal more. In general, such references are written by divers, and not research scientists, and they often contain vague or even inaccurate statements, and not infrequently opinions presented as fact. Information at the level you are talking about really does have to be extracted from more scientific publications -- the Rubicon Research Repository is an excellent place to look for same (see the link in my sig line). But you should also be aware that there is a great deal that simply is not known about staged decompression diving. The GUE DVD, "The Mysterious Malady", is a fascinating look into the minds of the people who are doing the little bit of research that is even being done on these topics.

 

[mmadiver]

I do not think ignoring the people who have been doing the actual research and testing for the better part of a century is a good way to go. I have not read any of the other books suggested but I am sure that all of them credit the US Navy Diving Manual as one source for their information.

No doubting USN experience on the subject and the dive manual is a good reference for sure. However it is primarily intended as an operational manual for Navy dive ops and doesn't contain much specific NEDU test data or 'theory', rather it summarizes the findings to provide context for current Navy dive procedures.

If your interested in the science and a more comprehensive discussion of gas physics (as the OP requested) you're better off with the listed civilian publications or reading specific NEDU case studies and reports.

 

[rjack321]

Can you recommend me a book or articles related to trimix diving that contain an in-depth, quantitative, properly referenced discussion of breathing, gas switches, hypoxia, carbon monoxide, carbon dioxide, helium, gas density and pressure?

Nobody is writing books about carbon monoxide and diving. Operationally it is produced during fills from either the entrainment of combustion gases (compressor intake near idling vehicles) or in situ in the compressor from the partial combustion of compressor oil - particularly in hot weather (e.g. >30C). Its toxicity is directly related to its partial pressure. So at 60m (7 ATA) a surface concentration of 20 ppm (survivable if the exposure was short enough) would be 140 ppm (rapidly fatal).

Carbon monoxide can be converted to carbon dioxide in compressor filters using a catalyst called hopcalite. Hopcalite must be completely dry and oil free to function and the applied CO concentration can't be too high or it will be overwhelmed and fail to catalyze all the CO. One reason why there are so many CO issues in the tropics is that compressors are poorly installed (small hot rooms), and often poorly maintained as well. You can buy a CO detector from several possible suppliers. You want one reading to zero, and any detectable CO at all is a good reason to not dive. This is because they are all calibrated at roughly 100pm and their reliability near zero is questionable. Hence if you get 1 or more ppm CO get another fill.

 

[Subcooled]

Why are you looking for this?

I want to know how the hyperbaric conditions affect me.

---------- Post added November 17th, 2014 at 09:13 AM ----------

In general, such references are written by divers, and not research scientists, and they often contain vague or even inaccurate statements, and not infrequently opinions presented as fact.

I have noticed this. Although the presented ideas tend to work in practice (have until now, at least), I feel uneasy when I encounter them. Should I trust this often almost correctly motivated advice when diving deeper?

The Bennetts and Elliots book is promising. Deeper into diving - maybe.
Some books are a quarter of a century old, though.

the Rubicon Research Repository is an excellent place to look for same (see the link in my sig line)

An excellent resource indeed. I would appreciate some review articles and collections though

---------- Post added November 17th, 2014 at 09:29 AM ----------

Hopcalite must be completely dry and oil free to function and the applied CO concentration can't be too high or it will be overwhelmed and fail to catalyze all the CO.

A gas check with an Analox CO detector revealed 5-12ppm of CO in our trimix tanks once (car outside the filling station). The blender had believed that the filter... well... filters. Someone then asked if 5ppm really was a lot or not. I had no idea. I knew it was bad... but how bad? We chose not to dive. Now I want to be able to tell the effects of CO.

Wikipedia says that 400ppm causes headache, and 800ppm causes convulsions.
A post above states that 140ppm is rapidly fatal.

 

[Rhone Man]

It is a little bit dated now, but I am a big fan of Gary Gentile's Technical Diving Handbook: The Technical Diving Handbook: Gary Gentile: 9781883056056: Amazon.com: Books

He has a very pleasant writing style, and I found it really accessible when I read it as a non-tec diver, but not cutting edge.

Separately, I have always thought that there might be a good market if one of the great or the good decided to write Technical Diving Encyclopedia (similar to PADI's Recreational Diving Encyclopedia). I'd be happy to volunteer for the proof reading team.

 

[kr2y5]

It is a little bit dated now, but I am a big fan of Gary Gentile's Technical Diving Handbook: The Technical Diving Handbook: Gary Gentile: 9781883056056: Amazon.com: Books He has a very pleasant writing style, and I found it really accessible when I read it as a non-tec diver, but not cutting edge.

Me too, +1.

 

[lemke]

The "references and further reading" section in Mark Powell's book would be a good start. If you're looking for "black and white" answers for your questions, you will never find them. Understanding YOUR physiology is the first step in confirming deco theory and gas breathing.