How Do You Use Helium In Trimix?
Trimix is a mixture of helium, oxygen and nitrogen used as a breathing gas in deep dives. The air we normally breathe is 21 percent oxygen and 79 percent nitrogen. Below a depth of 130 feet, the pressure causes nitrogen to accumulate in the bloodstream causing nitrogen narcosis. The following steps will show you how to use helium to make trimix for use in open-circuit scuba diving. Step 1 Use a mixture of 19 percent oxygen and 30 percent helium for dives ranging from 100 to 200 feet. Unless otherwise specified, the remaining gas (51 percent in this case) is nitrogen. This particular mixture is known as “normoxic” trimix because its level of oxygen is almost the same as normal air. Step 2 Utilize a mixture of 10 percent oxygen and 70 percent helium for dives between 200 and 330 feet. This mixture is called “trimix 10/70” after the percentage of gases it contains. It is also known as “hypoxic” trimix because breathing it at normal pressure would quickly cause hypoxia. Step 3 Mix the gase
