NAUI Nitrox Exam Prep (New 2024/ 2025 Update) Questions and Verified Answers| 100% Correct, Exams of Marine Science and Biology

Download NAUI Nitrox Exam Prep (New 2024/ 2025 Update) Questions and Verified Answers| 100% Correct and more Exams Marine Science and Biology in PDF only on Docsity! NAUI Nitrox Exam Prep (New 2024/ 2025 Update) Questions and Verified Answers| 100% Correct| A Grade QUESTION The Signs and Symptoms of DCS Do Not Vary and Can Be Easily Identified No Matter The Injury or Severity of The Case (T/F) Answer: False QUESTION Central nervous system toxicity Answer: CNS toxicity can result from relatively short exposures to high partial pressures of oxygen. QUESTION The other type is called pulmonary toxicity or whole body toxicity Answer: Pulmonary toxicity results from prolonged exposure to elevated partial pressures of oxygen (above about 0.5 atmosphere). As the name implies, its most pronounced effects are on the lungs, producing signs and symptoms such as chest tightness, breathing discomfort and pain, shortness of breath, and coughing. Development of pulmonary toxicity requires long-term exposures such as encountered in saturation diving, certain military and commercial diving, or recompression chamber treatment. QUESTION Pulmonary toxicity is not a concern of the recreational nitrox diver; CNS toxicity is a concern. Answer: QUESTION Using the NOAA Oxygen Exposure limits the 24 hour limit at the maximum recreational partial pressure of oxygen (PPO2) is 200 minutes (T/F) Answer: False QUESTION Match each statement True or False: Answer: The mechanisms of nitrogen narcosis are thought to be similar to Anethesia: True A diver suffering from nitrogen narcosis will always be aware that he/she is impaired: False Argon in air is essential to sustain life: False The primary waste product from the metabolism of oxygen is Carbon dioxide: True A stuporous condition characterized by impaired mental and physical performance and changes in mood and behavior is known as nitrogen narcosis: True QUESTION For most persons, symptoms of hypoxia begin to appear when the PO2 ______________________ Answer: Falls below about 0.16 ata QUESTION The acronym used to remember signs and symptoms of oxygen toxicity is: QUESTION step 1: (28msw / 10msw) + 1ATM = 3.8 ATA step 2: 1.4ppo2 / 3.8ATA =0.368 fO2** rounding to safety=36% O2 Answer: Single-step calculation: (1.4 ppo2 /{(28msw/10msw)+1atm}) = 0.368fO2** rounding to safety=36% O2 QUESTION step 1: (95fsw / 33fsw) + 1 ATM = 3.88 ATA step 2: 1.4 ppo2 / 3.88 ATA = 0.3608 Fo2 rounding to safety=36% O2 Answer: Single-step calculation: (1.4 ppo2 /(95fsw/33fsw)+1atm) = 0.3608 fO2** rounding to safety=36% O2 QUESTION Match the term to its definition Answer: The maximum operating depth (MOD) of a gas mix is determined by: The maximum acceptable partial pressure of oxygen Best Mix: Is the highest percentage of oxygen that can be used at a partial pressure of 1.4 at the planned dive depth 32% and 36% oxygen: The two most commonly used nitrox mixtures, also known as NOAA Nitrox I and NOAA Nitrox II, are. QUESTION The "best mix" (not to exceed 40% O2) to use for an oxygen partial pressure limit of 1.6 ata on a dive to 27 msw (90fsw) is____________________________ Answer: EAN 40 QUESTION The two most commonly used nitrox mixtures, also known as NOAA Nitrox I and NOAA Nitrox II are: Answer: 32% and 36% oxygen QUESTION Calculate the maximum operating depth for EAN32 at a ppo2 of 1.4 __________________________ Answer: 34 msw (111 fsw) QUESTION Using Boyles law we can easily know that if you compared two 11 liter (80 cubic foot) scuba cylinders with different pressures to the one with double the pressure also has a greater volume of gas (T/F) Answer: True QUESTION Henry's Law Answer: The amount of any given gas that will dissolve in a liquid at a given temperature is a function of the partial pressure of the gas that is in contact with the liquid and the solubility coefficient of the gas in the particular liquid." QUESTION Henry's Law addresses the quantity of a gas that will dissolve, and describes the rate at which the gas will dissolve (T/F) Answer: False, it does not describe the rate at which gas disolves QUESTION Dalton Law States Answer: The total pressure exerted by a mixture of gases is equal to the sum of the pressures that would be exerted by each of the gases if it alone were present and occupied the volume. QUESTION According to Daltons law, the pressure exerted by each gas mixture will add up to the total pressure of gas (T/F) Answer: True QUESTION Converting between depth and pressure by formula (Metric) QUESTION The Oxygen Partial Pressure (PO2) in EAN35 at a depth of 26 msw (85 fsw) is Answer: 1.3 ata QUESTION The absolute pressure at 17 msw (56 fsw) is Answer: 2.7 ata QUESTION What is the partial pressure of oxygen in the air at a depth of 21 msw (69 fsw) Answer: .65 QUESTION If the oxygen partial pressure in your mix is 1.3 ata at a depth of 37 msw (122 fsw), what is the fraction of oxygen in the mix Answer: .28 QUESTION At one atmosphere absolute there is 79% nitrogen or a partial pressure of 0.79 nitrogen as a diver descends the percentage of gas doesnt change but the partial pressure of the gas will increase with increased pressure (T/F) Answer: True QUESTION NAUI Dive tables can be used from sea level to an altitude of 300m (1000ft), NAUI RGBM from sea level 610m (2000ft) for altitudes beyond that divers should use altitude dive tables (T/F) Answer: True QUESTION All RGBM dives should have a 3-minute safety stop at 5msw (15 fsw) (T/F) Answer: True QUESTION Equivalent Air Calculations (EAN32 to a depth of 24.2 meters (80 feet)? Answer: QUESTION Metric tep 1: (24.2msw/10msw)+1atm=3.42ata Step 2: {(1.0-0.32) / 0.79 } * 3.42ata = 2.94ata Step 3: (2.94 ata - 1 atm) * 10msw = 19.4msw EAD Rounding to safety=21msw EAD for a dive table Answer: Single-step calculation: [{(24.2msw+10)*(1.0-0.32)}/0.79]-10msw=19.4mswRounding to safety=21msw EAD for a dive table QUESTION Imperial Step 1: (80fsw/33fsw)+1atm=3.42ata Step 2: {(1.0-0.32) / 0.79 } * 3.42ata = 2.94ata Step 3: (2.94 ata - 1 atm) * 33fsw=64fsw EAD Rounding to safety=70fsw EAD for a dive table Answer: Single-step calculation: [{(80fsw+33)*(1.0-0.32)}/0.79]-33fsw=64fswRounding to safety=70fsw EAD for a dive table QUESTION A diver using EAN32 makes a dive to 33msw (110 fsw) for 23 minutes. After a surface interval of 2 hours they make a second dive (also using EAN32) to 23 msw (75 fsw). Using NAUI EAN32 Dive Tables, the adjusted maximum dive time for the second dive is ____________________ If the same diver was using NAUI RGBM EAN32 Dive Tables, the maximum dive time for the second dive would be ___________________ Answer: 11, minutes, 47 minutes QUESTION Match Terms Answer: Answer: Partial pressure mixing: Uses a measured pressure of oxygen is added to a cylinder, which is then filled to service pressure with air Continuous-flow: Uses an injected a measured flow of pure oxygen into the air before it reaches the intake of the compressor Pre-mix: Uses gas supplier will usually mix the oxygen and nitrogen by weight to prevent errors Membrane Separation: Uses a semi-permeable membrane that allows oxygen to flow through it more readily than nitrogen Pressure swing absorption: Uses a material called a molecular sieve that selectively absorbs a thin layer of nitrogen from the air that passes over or through it QUESTION cylinders and tank valves to be used with enriched air must be cleaned and oxygen-compatible lubricants used. Answer: QUESTION Petroleum-based lubricants are not used with high-pressure oxygen because they may ________________ Answer: Ignite and burn extremely easily QUESTION Any equipment that is used with pure oxygen or an oxygen level above _____________ must be cleaned for oxygen service. Although you will not be using nitrox mixtures above ________________ oxygen, your cylinder should be cleaned and identified as a nitrox cylinder because ___________________________________________ Answer: 40%, 40%, It may be subjected to pure oxygen at elevated pressures when it is filled QUESTION Nitrox analyzers never need maintenance or to be calibrated (T/F) Answer: False QUESTION When analyzing a nitrox blend the ___________ must be the same as when the unit was calibrated with air Answer: flow rate QUESTION After the gas is analyzed and the cylinder is labeled, the diver must Answer: Document the fill by completing an entry in the fill log QUESTION Final gas analysis and recording the pertinent information in a fill log and on the cylinder is the responsibility of the __________________ Answer: end user QUESTION Place the steps for calibrating in the correct order Answer: Ask for help if you are not familiar with the analyzer Calibrate the analyzer to a known source following proper protocol Open the cylinder to be analyzed and establish the correct flow rate for the analyzer being used label the cylinder fill out the Nitrox log book QUESTION Air Answer: 78% Nitrogen, 21% Oxygen QUESTION What is Nitrox Answer: Gas mixture with less Nitrogen (usually more Oxygen) QUESTION Nitrox other names Answer: Oxygen enriched air, Enriched air nitrox, Nitrox, EANx. 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