Heliair

Heliair is a breathing gas consisting of mixture of oxygen, nitrogen and helium and is often used during the deep phase of dives carried out using technical diving techniques. This term is mostly used by Technical Diving International.

Additional recommended knowledge

Essential Laboratory Skills Guide

How to ensure accurate weighing results every day?

Daily Sensitivity Test

It is easily blended from helium and air and so has a fixed 21:79 ratio of oxygen to nitrogen with the balance consisting of a variable amount of helium.

See also trimix and heliox.