Counterdiffusion discussion

[Mdemon]

Found this on Scubaboard - we didn't get much interest in the couterdiffusion question by Johnmaneely and I was curious...

Check the names involved...!

http://www.scubaboard.com/showthread...hreadid=20261&

[Finless]

John,

Wish I could help with some sensible comments. With topics like this I do not have the knowledge to know if the theory makes sense or not. I rely on other people to work things out and test their theories. It all sounds emminently sensible/plausible and for the most part not a worry as the gas switching described is what trimix divers do anyway (AFAIK) and I'm sure no one puts helium in their dry suit. I've never heard of anyone having a "bent ear"?

As I don't do helium mixes (yet) I have not been in a position to notice such effects. Have you noticed any of the effects described?
Also, I work on the theory that I don't need to know how things work, only that they do (eg deep stops).

Bryan

[Mark Chase]

Mark Elliot used a high Helium content for suit inflation on his record dive to avoid counter diffusion issues.

He strongly believes its a major issue in deep diving beyond 100m but I am not qualified to give detailed synopsis of his case I can only direct you to his web site. I have a beta copy of his new decompression soft where which uses stuff like 50/50 for deco. It’s hard going but interesting when you can get it to work.

http://www.inspired-training.com/

ATB


Mark Chase

[Finless]

Originally Posted by Mark Chase

Mark Elliot used a high Helium content for suit inflation on his record dive to avoid counter diffusion issues.

Mark,

Do you think that the potential for being cold due to using high helium content gas for suit inflation may cause other complications due to consequent restriction of blood flow to the skin?

Bryan

[EDIT]Ignore that - dumb question.

[db8us]

In my opinion isobaric counterdiffusion can be done in lab-experiments or occur under bizarre circimstances, like one is saturated with AIR and the switches to Trimix and stay on the same depth....
But i would like to quote GI on that one:
Isobaric counterdiffusion occurs when the easter bunny sucks Santa Clauses dick.
Well, i do not know how often this happens, but i would put in in the same category.
The ICD is so boring, i would not even had posted to this thread, but i like this classic of GI too much ;-)

[NotDeadYet]

I've heard of it happening in habitats where the environment gas was one thing but the BIBS supply was something different. I was once asked to include ICD calculations in XS. I looked at it and decided it wasn't worthwhile. I think there are many things that will kill you before ICD does.

[Drmike]

Originally Posted by db8us

Isobaric counterdiffusion occurs when the easter bunny sucks Santa Clauses dick.

I do miss George

[ahar]

Great thread - very interesting to see Bruce Weinke (deco theory demi-god) posting

[NotDeadYet]

Originally Posted by ahar

Great thread - very interesting to see Bruce Weinke (deco theory demi-god) posting

It's even better to see him posting sensibly. His rants on the Decompression List were on a par with George's on Techdiver.

I guess this is adding to what I've come to believe, that OC trimix is dead. Use rebreathers, no gas switching needed, one less thing to worry about.

[And]

Originally Posted by NotDeadYet

I guess this is adding to what I've come to believe, that OC trimix is dead. Use rebreathers, no gas switching needed, one less thing to worry about.

LMAO (spits coffee all over keyboard)