Alternative gases

[divetheworld]

With the problem I am having using my FFM with comms on He, I was discussing this with an old commercial diving pal who suggested Neon. unfortunately as a Comm diver, he uses diving as a means to get to work and knows little of what I need. He is attempting to get me his AMG copy of Abyss which should help.
As I can get this gas for much less than most can get He I think it would be worth considering, but I can find little information to allow me to get the "full picture".
As far as I can see, it has a soluability similar to He, which should mean that deco tables might be on a par-ish, but I am unsure as to Partial pressure limits and effects.
The Abyss software might help, but this will mean backward engineering the philosophy, not ideal.

Does anyone have any information relating to the use of Neox?

Please dont just google and post quotes.

[NotDeadYet]

From what I remember it was very tricky to treat neon bends and this was why it never caught on. It should be easy enough to interpolate the a/b values and halftimes for neon and plug them into deco software (IIRC DDPlan lets you do this).

[beanie]

there's bits in Rob Palmers book on differnt gases.
there was a site which had properties of gases size and narcotic effects
http://www.techdiver.ws/exotic_gases.shtml#3.2

seem to indicate that it has lower solubilty than nitrogen Abyss agrees
http://www.abysmal.com/web/library/a...of_helium.html

hmmm let us know how you get on

[divetheworld]

Originally Posted by NotDeadYet

From what I remember it was very tricky to treat neon bends and this was why it never caught on. It should be easy enough to interpolate the a/b values and halftimes for neon and plug them into deco software (IIRC DDPlan lets you do this).

I'll have to look at trying this out in the software, does anyone know how reliable this is?
I suppose I would have to put in a margin of error and some fairly large amounts of conserv to try it out, but that kinda defeats the point.
I need a bit more info before I mix a normoxic neox in the dil tank and try it out.
I dont plan on getting bent just quite yet!!!

[NotDeadYet]

It's just the same procedure that Buhlmann used for working out the helium values. You just multiply the N2 figures by a factor related to the gas's molecular weight. It's in all the deco textbooks.

[nigelH]

Originally Posted by divetheworld

an old commercial diving pal who suggested Neon.

The big snag with neon is that it is fantastically expensive.

[The Purist]

Originally Posted by nigelH

The big snag with neon is that it is fantastically expensive.

But surely you just need a transparent canister on your RB, a bit of leccy and you are the coolest diver in the water - bling for the RB diver

<edit>
read the first post, deleted all the crap about Abyss
</edit>

[NotDeadYet]

Isn't there a neon/oxygen mix which is formed as a by-product of cracking oxygen (or could be helium) from it's crude form which is dirt cheap?

[Ant P]

Originally Posted by divetheworld

With the problem I am having using my FFM with comms on He, I was discussing this with an old commercial diving pal who suggested Neon.

What problem are you having with your FFM comms and He? If it is just the sound of the voice, wouldn't it be an option to simply put some preprocessing in the comms to slow the sound down back to its 'normal' state. There seem to be plenty of mobile phone engineers on here who would know the details.

Of course if its nothing to do with that then please ignore me.

Cheers, Ant

[divetheworld]

Originally Posted by Ant P

What problem are you having with your FFM comms and He? If it is just the sound of the voice, wouldn't it be an option to simply put some preprocessing in the comms to slow the sound down back to its 'normal' state. There seem to be plenty of mobile phone engineers on here who would know the details.

Of course if its nothing to do with that then please ignore me.

Cheers, Ant

We use OTS buddII phones. They are potted, no access to the components.

It is voice intelligibility that is the problem. Especially with the surface units.

I have a cyl of Ne arriving tomorrow.
Its worth a try.