Scuba Diving International (SDI) Computer Nitrox Practice Exam

A mixture of nitrogen and oxygen with an increased percentage of oxygen is called what?

1. Enriched Air

2. Compressed Air

3. Regular Air

4. Pure Oxygen

The correct answer is: Enriched Air

A mixture of nitrogen and oxygen that includes an increased percentage of oxygen is referred to as Enriched Air. This term is commonly used in diving to describe a gas blend that typically contains between 21% and 40% oxygen, which is higher than the 21% found in regular atmospheric air. The elevated oxygen percentage allows divers to extend their bottom time and reduce the risk of nitrogen narcosis during dives. Unlike Compressed Air, which contains the usual proportions of nitrogen and oxygen found in the atmosphere, or Regular Air, which is the same as ambient air with no alterations, Enriched Air is specifically processed to increase the oxygen content for diving purposes. Pure Oxygen, on the other hand, contains 100% oxygen and is typically not used for diving without special considerations due to the risks associated with high-pressure oxygen exposure. Understanding these distinctions is vital for divers aiming to utilize Enriched Air safely and effectively in their underwater endeavors.