Argon and Helium

[TheDarknessLord]

Hi!

I want to start with my trimix course, but first I would like to study a little bit before my classes.
Do you know if Argon can be breath as a mix air, or it is only used for the dry suit?
Where I can find articles or good books about it.

Tks a lot!

 

[BillP]

Howdy TheDarknessLord:

Can you use argon in your breathing mix? Yes, you can. But then you have to ask, "Why on Earth would you want to?" Argon is more narcotic than nitrogen, it is denser (and therefore more difficult to breathe at depth) than nitrogen, its solubility characteristics are less favorable for decompression than nitrogen, and it's a whole lot more expensive than nitrogen. I can't think of any reason for you to add it to your breathing mix. If you need to reduce the nitrogen in your breathing mix with an inert gas, use helium.

There's also some question about argon's utility as a drysuit inflation gas, but that's another story.

HTH,

Bill

 

[dmdalton]

Only for the drysuit as it is highly narcotic (more so than N2). However, I've only used air in my argon bottle and been fine breathing trimix with as much as 55% HE on dives up to 90 min run time in 42 degree water. Trilam suit with Andy's US140 undergarment.

For books I'd suggest you get the O2 Hackers Companion from Airspeed Press

http://www.airspeedpress.com/

Dave D

 

[Dryglove]

http://thedecostop.com/forums/showthread.php?s=&threadid=334&highlight=helium

 

[GearHead]

I hear that the kids these days have stopped sniffing glue in favor of breathing Argon mixes at depth. :rasta:

It can be done, but after sucking down some Argon, you might be so intoxicated that you would try to breathe some H20. Bad voodoo, man.

 

[Dr Deco]

Dear “Darkness”:

Argon

BillP has given many reasons why this gas is a bad idea for diving. It is not particularly rare, being in our atmosphere in a concentration of 1%, and people think of it often where diving is concerned.

Mechanism of Decompression Sickness

My particular view is from the aspect of decompression. Argon is very soluble in adipose (= fat) tissue. In a bad situation, gas bubbles are released from adipose tissue into the blood stream (specifically the fat tissue capillaries and then the venous return) when they move to the heart and lungs.

If large volumes of gas bubbles reach the lungs, it is possible that pressures rise and some bubbles are arterialized, it, they pass into the systemic arterial system. When the large bubble volumes appear in conjunction with fluid shifts (e.g., while in the water, or semi-recumbent on the boat deck) and Valsalva-like maneuvers (e.g., straining, coughing), arterialization increases in probability. You do not want this to happen.

Avoidance of DCS

You avoid this by, one, not having a large amount of fat tissue, and two, not breathing a fat-soluble gas, such as argon.

This is not theoretical. You can definitely see this in laboratory studies with rats where the breathing gases are helium, nitrogen or argon. We have a great deal of data on lab rats but none on humans. You do not want the dubious honor of becoming the first data point!

Dr Deco :doctor:

Please note the next class in Decompression Physiology
http://wrigley.usc.edu/hyperbaric/advdeco.htm