Quote: (Originally Posted by smekke)
Didn't know that. I assumed adding He is good because it's more easy to breath (better ventilation, less chance for CO2 buildup).
Any references to studies or experiments which indicate the positive pN2 impact on oxtox ?
Many Thanks
Peter
What saturation is talkng about is studies and dives that have been acomplished on very high pn2 loads.
N2 has the effect of slowing down the nervous system (retarding xmission fro the neurons), which is probably why this effect has been seen... while He allows the neuorons in the brain to communicate more easily...
This also is probably the reason why someone switching to an oxygen rich deco mix, is much more likely to tox than someone diving air very deep...
There have been air dives to over 450fsw with little problems other than SEVERE narcosis, but someone swicthing to oxygen at 60fsw is much more likely to tox at the same oxygen exposure..
A helox based deco mix will also have ahigher risk of toxing than a nitrox deco mix..
More helium isnt always better.. I have also discussed this matter many times with an HSE hyberaric chabmer trainer, and he told me that the incidence of tox effects is definately higher when they use heliox 50 for their schedules over the same exposures with oxygen only.