Posted by tleemay on January 02, 2001 at 15:29:08:
In Reply to: Newbies... posted by mattschechter on December 29, 2000 at 20:51:02:
"I may also hear of something I didn't know
existed in diving (some of the tech stuff for
example). This certainly doesn't mean that I'm
going to sign up for the next Materhorn trip and
switch to DIR with a back-plate, doubles, and
gasses not found on the periodic table."
Being a newbie, how much exposure have you had
to diving with a BP/wings? Would you like some?
All you have to do is speak up and I know of at
least two on this board that will give you the
chance to experience it first hand.
And the gasses commonly used for mixed gas diving
are certainly on the periodic tables ... but then
again you already knew that and were jerking our
bungies, right?!?!
Off the 1999 Periodic Table by CalTech Pasadena
Oxygen (O2)
Atomic designation O
Atomic number 8
Atomic weight 15.9994 am units
Nitrogen (N2)
Atomic designation N
Atomic number 7
Atomic weight 14.00674 am units
Argon (Ar)
Atomic designation Ar
Atomic number 18
Atomic weight 39.948 am units
Helium He
Atomic designation He
Atomic number 2
Atomic weight 4.002602
Note that small molecular atomic weight of Helium.
It is substantially less than nitrogen. It's exactly
3.4994086 am units less, which means it will off
gas from similar tissues almost 3.5 times faster than
nitrogen. It also on gasses faster, but causes less
potential damage to the tissues during the on/out
gassing periods.
Now if cost were not an issue, would you prefer to
do a dive to 100'+ on O2 and N2, or have part of that
N2 content replaced by a friendlier gas? A gas that
will take less toll on your body tissues over a dive
cycle?