Argon for Diving? Really?
Well, before we get to the diving part, let's talk about what Argon is and its special properties:
Atomic Number: 18
Argon is the third most common gas in the earth’s atmosphere and the third lightest noble gas. Most argon found today is from the decay of potassium 40 in the earth's crust. Argon is derived from the Greek word αργον meaning "lazy" or "the inactive one" and is due to the element’s nature of undergoing almost no chemical reactions. Industrially argon is produced by the fractional distillation of liquid air.
Argon was first suspected by Henry Cavendish in 1785 but it was not until 1894 that Lord Rayleigh and Sir William Ramsay in Scotland isolated the gas from air.
Argon gas is mostly used as a shielding gas in welding and other high-temperature industrial processes today due to its low reactivity. Argon is also used in incandescent and fluorescent lighting and other types of gas discharge tubes.
Now for the diving part.....
Argon is being used more and more as a drysuit inflation gas. When trimix started being used by recreational divers, they found that they tended to get colder faster due to the high thermal conductivity of helium. So they started carrying small tanks of air just for drysuit inflation. They finally figured out if we are going to start carrying extra bottles of air for this, then we might as well get the "warmest" gas possible. Argon is a lot less conductive than helium and air but still readily available and not too expensive.
While Argon tanks are transfilled just like oxygen or air, there are not a lot of special handling rules for it as it is not combustible. Don't get careless with it, but Argon will not ignite or flash like oxygen might.
Argon is NOT a life support gas. You cannot put a regulator on it and use it as a safety gas option. For this reason, we always clearly mark our tanks with ARGON stickers and NON-BREATHABLE GAS markings.
More and more manufacturers are coming out with Argon inflation systems. The Academy of Scuba rents and sells the XS Scuba Argon System and provides Argon tank fills for $10 per fill. To purchase your Argon System Click Here.
Swanepoel, Anton. The Art of Gas Blending.
Harlow, Vance. Oxygen Hacker's Companion