NITROX CERTIFICATION COURSE EXAM
QUESTIONS WITH CORRECT ANSWERS
What is Nitrox - Answer-Nitrox contains a higher percentage of oxygen, unlike air which
normally contains approximately 79 percent nitrogen and 21 percent oxygen.
Nitrox primary benefits - Answer-extend your bottom times and to shorten your surface
intervals significantly compared to your previous air-dives
what is EAN32: - Answer-enriched air nitrox with 32% oxygen : 68% nitrogen
FO2 is 32 (Fraction of Oxygen)
what is EAN36: - Answer-enriched air nitrox with 36% oxygen : 64% nitrogen
How long, in any 24-hour period, you can be exposed to a Nitrox mixture at its
maximum operating depth (MOD)? - Answer-you will have a cumulative time limit for
oxygen exposure at the maximum operating depth(MOD) of 2:30 hours in any 24-hour
period
How long, in a single dive, can one be exposed to a Nitrox mixture at its maximum
operating depth(MOD) - Answer-the oxygen exposure time limit for a single dive is 45
minutes at a given maximum operating depth(MOD)
What is Advanced Nitrox - Answer-Gas mixtures containing more than 40% oxygen are
sometimes called Advanced Nitrox or Technical Nitrox.
Normal Air that we breathe is comprised of what % oxygen and nitrogen - Answer-21%
oxygen and 79% nitrogen
How can a dive computer help you avoid decompression sickness? - Answer-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? - Answer-you must
stop at a particular depth to allow the excess nitrogen in your body time to escape
without causing problems.
What does the term decompression stop mean? - Answer-Your computer may require
you to make one stop or a series of stops, commonly known as decompression stops.
What are three reasons why sport divers should avoid decompression diving? - Answer-
decompression diving requires specialized training, additional equipment, and topside
support.
, What is the primary cause of decompression sickness? - Answer-occurs when you have
an excess amount of nitrogen in your body and you ascend too quickly. The nitrogen
comes out of a solution and forms a bubble thus disrupting the flow of blood in whatever
part of the body it is located
What are the most common symptoms of decompression sickness? - Answer-pain in
the joints, numbness, paralysis, loss of balance, muscle weakness, and impaired
thinking
What is the recommended first aid for decompression sickness? - Answer-treating the
diver for shock by laying them down, provide an injured diver pure oxygen as soon as
possible and transport to a hyperbaric chamber and keeping them either from being to
cold or too warm
What is the minimum concentration of oxygen required to maintain consciousness at
sea level? - Answer-gas mixtures containing as little as 16% oxygen
What is the maximum percentage of oxygen that sport divers use in a Nitrox mixture? -
Answer-40%
What is the maximum recommended depth for using 100 percent oxygen? - Answer-6
meters
Equivalent Air Depth(EAD) - Answer-a dive to depth on Nitrox is equivalent to a making
a dive of a shallower depth on air (less nitrogen gets absorbed by body, less
decompression obligation)(more oxygen available, dangerous to pass MOD)
What is the MOD for EAN32? - Answer-40 meters or 132 feet (max depth for open
water)
What are two reasons why EAN32 is a good choice for Nitrox diving? - Answer-good
combination of extended bottom time and unrestricted depth within the sport diving
range, using EAN32 poses less risk in terms of exposure to oxygen than other richer
mixtures
What is the maximum partial pressure of oxygen (PO2) we use in Nitrox diving? -
Answer-a P02 of 1.6
Breathing 100% oxygen at 6 m/20 ft of sea water is the equivalent of breathing EAN32
at 40 m/132 ft of sea water in terms of oxygen partial pressure. - Answer-Facts
What does the term oxygen toxicity mean? - Answer-physiological reaction of your body
that occurs when you are exposed to breathing mixtures containing high partial
pressures of oxygen, or mixtures containing lower partial pressures of oxygen for
extended periods
QUESTIONS WITH CORRECT ANSWERS
What is Nitrox - Answer-Nitrox contains a higher percentage of oxygen, unlike air which
normally contains approximately 79 percent nitrogen and 21 percent oxygen.
Nitrox primary benefits - Answer-extend your bottom times and to shorten your surface
intervals significantly compared to your previous air-dives
what is EAN32: - Answer-enriched air nitrox with 32% oxygen : 68% nitrogen
FO2 is 32 (Fraction of Oxygen)
what is EAN36: - Answer-enriched air nitrox with 36% oxygen : 64% nitrogen
How long, in any 24-hour period, you can be exposed to a Nitrox mixture at its
maximum operating depth (MOD)? - Answer-you will have a cumulative time limit for
oxygen exposure at the maximum operating depth(MOD) of 2:30 hours in any 24-hour
period
How long, in a single dive, can one be exposed to a Nitrox mixture at its maximum
operating depth(MOD) - Answer-the oxygen exposure time limit for a single dive is 45
minutes at a given maximum operating depth(MOD)
What is Advanced Nitrox - Answer-Gas mixtures containing more than 40% oxygen are
sometimes called Advanced Nitrox or Technical Nitrox.
Normal Air that we breathe is comprised of what % oxygen and nitrogen - Answer-21%
oxygen and 79% nitrogen
How can a dive computer help you avoid decompression sickness? - Answer-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? - Answer-you must
stop at a particular depth to allow the excess nitrogen in your body time to escape
without causing problems.
What does the term decompression stop mean? - Answer-Your computer may require
you to make one stop or a series of stops, commonly known as decompression stops.
What are three reasons why sport divers should avoid decompression diving? - Answer-
decompression diving requires specialized training, additional equipment, and topside
support.
, What is the primary cause of decompression sickness? - Answer-occurs when you have
an excess amount of nitrogen in your body and you ascend too quickly. The nitrogen
comes out of a solution and forms a bubble thus disrupting the flow of blood in whatever
part of the body it is located
What are the most common symptoms of decompression sickness? - Answer-pain in
the joints, numbness, paralysis, loss of balance, muscle weakness, and impaired
thinking
What is the recommended first aid for decompression sickness? - Answer-treating the
diver for shock by laying them down, provide an injured diver pure oxygen as soon as
possible and transport to a hyperbaric chamber and keeping them either from being to
cold or too warm
What is the minimum concentration of oxygen required to maintain consciousness at
sea level? - Answer-gas mixtures containing as little as 16% oxygen
What is the maximum percentage of oxygen that sport divers use in a Nitrox mixture? -
Answer-40%
What is the maximum recommended depth for using 100 percent oxygen? - Answer-6
meters
Equivalent Air Depth(EAD) - Answer-a dive to depth on Nitrox is equivalent to a making
a dive of a shallower depth on air (less nitrogen gets absorbed by body, less
decompression obligation)(more oxygen available, dangerous to pass MOD)
What is the MOD for EAN32? - Answer-40 meters or 132 feet (max depth for open
water)
What are two reasons why EAN32 is a good choice for Nitrox diving? - Answer-good
combination of extended bottom time and unrestricted depth within the sport diving
range, using EAN32 poses less risk in terms of exposure to oxygen than other richer
mixtures
What is the maximum partial pressure of oxygen (PO2) we use in Nitrox diving? -
Answer-a P02 of 1.6
Breathing 100% oxygen at 6 m/20 ft of sea water is the equivalent of breathing EAN32
at 40 m/132 ft of sea water in terms of oxygen partial pressure. - Answer-Facts
What does the term oxygen toxicity mean? - Answer-physiological reaction of your body
that occurs when you are exposed to breathing mixtures containing high partial
pressures of oxygen, or mixtures containing lower partial pressures of oxygen for
extended periods
