Appendix A
A82PPENNAUDI NIXitro Ax Diver Answers to “Verify What You Have Learned”
Questions and Sample Problems
CHAPTER 1
Introduction
1. The nitrogen in the air limits the depth to which
you can dive, the time you can stay at depth, and
the number of dives you can make in a day.
2. Oxygen-Enriched Air,
Enriched Air Nitrox,
Nitrox
3. When diving, the increased pressure of depth
causes additional nitrogen to be dissolved in our
tissues.
4. Decompression sickness
5. Dr. Morgan Wells
6. 1992
7. Extend bottom time, shorten required surface
interval, safety margin, less physically tired
(fatigue)
8. 15-33 meter (50-100 foot) depth range
9. Oxygen percentage
10. Percentage. Fraction.
CHAPTER 2
Gases and Gas Mixtures
1. Its proportion in the mixture.
2. 21%; 79%
3. Alcohol intoxication
4. Energy
5. Boyle's Law
6. Henry's Law
7. Partial pressure
8. Dalton's Law
9. 10 meters (33 feet)
10. 3 ata
11. One atmosphere for the sea level air pressure.
12. Gas fraction, absolute pressure.
13. 1.16 ata
CHAPTER 3
The Physiology of Diving and Nitrox
1. Nitrogen narcosis.
2. Gases used in general anesthesia.
3. Ingassing; offgassing.
4. Excessive fatigue, weakness and tingling in
limbs, limb and joint pain and dysfunction, skin
rashes and itching, vertigo, loss of sensation,
paralysis, death.
5. Carbon dioxide
6. When the partial pressure of oxygen falls too
low.
7. Short exposure to high partial pressure of
oxygen. Prolonged exposure to elevated partial
pressure of oxygen.
8. 1.4 ata
9. Heavy exercise, increased carbon dioxide
buildup, chilling, water immersion.
10. Convulsions, visual disturbances, ears, nausea,
twitching and tingling, irritability, dizziness or
dyspnea.
CHAPTER 4
Choosing the Best Nitrox Mix
1. 32% and 36% oxygen.
2. Maximum Operating Depth (MOD) is the
maximum depth that should be dived with a
given nitrox mixture.
3. 28 msw (95 fsw).
4. Find the total pressure that it takes to produce
the maximum acceptable oxygen partial
pressure, and then convert it to a depth.
5. 21%-40%.
6. The highest fraction or percentage of oxygen
that can be used at the target depth.
7. 35%
8. Convert target depth into absolute pressure.
Next, determine the fraction of oxygen in
the mixture that will produce the maximum
acceptable PO2 at that absolute pressure.
CHAPTER 5
Dive Tables and Dive Computers
1. U.S. Navy Dive Tables; Reduced Gradient
Bubble Model.
2. + 1%
3. 10 minutes; 1 hour.
4. 300 meters (1000 feet)
5. 12 hours; 18 hours.
6. You can switch mixtures and tables from dive to
dive.
7. Equivalent Air Depth (EAD) is determined by
the partial pressure of nitrogen that the diver is
actually breathing.
8. 27 msw (80 fsw)