Nitrox Certification Practice Exam Questions and Correct Answers

What are the common terms divers may use when referring to Nitrox? -In all likelihood, you have also heard it referred to by a variety of names: enriched air, oxygen enriched air, SafeAir®, Denitrogenated Air®, EAN, EANx, NOAA Nitrox I or NOAA Nitrox II. What are the primary component gasses found in air, and the percentage of the total gas mixture each gas represents? - However, unlike air which normally contains approximately 79 percent nitrogen and 21 percent oxygen, Nitrox contains a higher percentage of oxygen. What does term Nitrox mean? -Nitrox a mix of nitrogen and oxygen just like air. What do divers commonly call a person who creates the Nitrox used to fill scuba cylinders? -Blender What are some of the common Nitrox mixtures used by divers? 22-40 percent mixture -EAN32: 68 percent nitrogen, 32 percent oxygen. -EAN36: 64 percent nitrogen, 36 percent oxygen. What are the two primary benefits divers enjoy by using Nitrox? -The first is that you can increase your maximum allowable bottom time. This happens because the extra oxygen added to your breathing gas when it was filled has displaced nitrogen. Because there is less nitrogen in the mix to be absorbed by your body you can spend longer at depth before you reach the nitrogen limit - which is the decompression limit. -Secondly, since you are absorbing less nitrogen on a given dive, your surface intervals can usually be shortened. State how long, in any 24-hour period, you can be exposed to a Nitrox mixture at its Maximum Operating Depth (MOD)? -Also, over the course of a 24-hour period, you will have a cumulative time limit for oxygen exposure at the maximum operating depth of two and a half hours in any 24-hour period. How can a dive computer help you avoid decompression sickness? -When you use a dive computer, it will calculate approximately the amount of nitrogen absorbed by your body, and indicates when it is time to ascend and the rate at which it is safest to ascend. What may happen if you go too deep or stay too long during a dive? -However, if your dive lasted for a long time, or you made a deep dive, the dive computer will indicate that you must stop at a particular depth to allow the excess nitrogen in your body time to escape without causing problems. Your computer may require you to make one stop or a series of stops, commonly known as decompression stops.