Nitrogen off gas on EANx

[The Chairman]

The solubility of gas into a solution is called "Henry's Law". You can find a simple explanation for it here: http://scidiv.bcc.ctc.edu/wv/09/0009-006-henry.html

The "difference" between the partial gas pressure and the disolved pressure of the same gas is called "tension". Gas is ALWAYS trying to achieve equilibrium. Consequently the higher the tension, the quicker the transfer.

Since the lungs are designed for an efficient transfer of gasses, have an unusally high tension at this interface does not cause difficulties.

 

[Dive-aholic]

Unfortunately, there's a lot of nonsense that's been written. The problem is that this is, fundamentally, a highly technical topic, and writing about technical subjects for non-technical audiences is very difficult...

Right, but this statement came from their DSAT Tec Deep book, intended for technical dive students. It's way too basic IMO.

At the other extreme is just about anything by Bruce Weinke. His titles usually have the word "basic" in them, but he's got a PhD in Physics, so what he considers "basic" is what most of us would consider advanced. I majored in Physics in college, but that was a long time ago. I recognize the things he's talking about, and remember being able to apply them, but there's a lot of what he says that I don't follow.

Do you have Basic Decompression, Theory and Application by Bruce Wienke?
It is far more in depth than the typical dive texts. There is a lot of math and physics, but as the author told me there is enough text to understand the material without having to do the math. I understand the physics but it has been way too long since I have done that kind of math. I think you would like the book.

I have the book. I started reading it a while back, but it can get difficult to understand. I'll have to pull it out again.

ND, thanks for the link. I do understand Henry's Law and the basic principle. I think what confused me was PADI's oversimplification of the process.