Enriched Air Diver Exam VERSION A- METRICEnriched Air Diver Examination METRIC VERSION A Please use the separate answer sheet. Do not write in this exam booklet . You may use a pen or pencil, scrap paper, calculator and all tables used during the course. Question 1 Question 5 For the purposes of recreational no decompression diving, what is "enriched air"? A. Any mix of nitrogen and oxygen other than air. B. Air that has had oxygen added or nitrogen removed so that it contains up to 40% oxygen. C. Air that has had oxygen added or nitrogen removed so that it contains up to 90% oxygen. D. None of the above. What is the primary concern regarding enriched air and scuba equipment? A. Keeping enriched air regulators from being confused with air regulators. B. Potential for fire/explosion due to contact with high oxygen content. C. Enriched air isn't usable in some BCDs. D. Dive computers cannot be used with enriched air. Question 2 Question 6 The basic principle behind enriched air is that because you replace some of the nitrogen you breathe with oxygen, and because your body metabolizes and absorbs oxygen, you absorb less nitrogen during the dive. True False Why does enriched air diving require a dedicated cylinder? A. To prevent enriched air from being confused with helium. B. To prevent enriched air from being confused with air. C. To prevent pure oxygen from being put into a cylinder that isn't oxygen serviced. D. Band C Question 3 How does using enriched air affect no decompression limits? A. It makes the no decompression limjts longer. B. It makes the no decompression limits shorter. C. It makes no decompression limits either longer or shorter, depending on the blend. D. It doesn't affect the no decompression limits. Question 7 What color coding, stickers and tags should an enriched air cylinder have? A. Green/orange band that says "enriched air," dated annual visual inspection sticker, contents sticker/tag and/or any markings required by local law. B. Yellow/green band that says "enriched air," contents sticker/tag and/or any markings required by local law. C. Yellow/orange band that says "enriched air," dated annual visual inspection sticker, contents sticker/tag and/or any marking required by local law. D. Yellow/green band that says "enriched air," dated annual visual inspection sticker, contents sticker/tag and/ or any markings required by local law. Question 4 What five disadvantages and/or potential hazards does enriched air have that air does not? A. Potential DCI, special equipment requirements, proper handling and blending, availability and lack of s uitable dive computers. B. Potential oxygen toxjcity, all equipment must meet 02 service standards, proper handling and blending, availability and more complex dive planning. C. Potential DC!, special e quipment requirements, proper handling and blending, availability and more complex dive planning. D. Potential oxygen toxicity, special equipment requirements, proper handling and ble nding, availability and more complex dive p lanning. 1 Enriched Air Diver Exam VERSION A- METRIC Question 8 What are the two primary concerns associated with filling enriched air cylinders? A. Potential for fire/explosion and obtaining a proper blend. B. Potential for fire/explosion and accidental overfilling. C. Proper blending and accidental overfilling. D. None of the above. Question 13 Using the Equivalent Air Depth Table, what are the actual maximum and contingency depth limits for EANx33? A. 25 metres and 35 metres B. 30 metres and 35 metres C. 30 metres and 40 metres D. 23.9 metres and 28.2 metres Question 14 Question 9 Using the Equivalent A.ir Depth Table, what is the oxygen partial pressure for a dive to 17 metres using EANx35? A. 1.23 ata B. 0.98 ata C. 0.91 ata D. 0.84 ata What should you do if an enriched air cylinder or oxygen serviced equipment is accidentally filled from a conventional air source? A. Nothing; this isn't a problem. B. Have the cylinder or equipment properly serviced and cleaned before being exposed to more than 40% oxygen again. C. Continue to use the equipment, but only with compressed air. D. Reduce the allowable oxygen content by 15%. Question 15 Using the Equivalent Air Depth Table and the Oxygen Exposure Table: A 60 minute dive to 21 metres using EANx38 results in how much oxygen exposure? A. 20% B. 25% c. 30% D. 35% Question 10 Using the air RDP and the Equivalent Air Depth Table: You plan to make two dives, the first with EANx36 and the second with EANx30. The first dive will be to 22 metres for 45 minutes, followed by a 73 minute surface interval. What will your no decompression limit and RNT be for a repetitive dive to 16 metres? A. 124 minutes no decompression limit and 23 minutes RNT B. 79 minutes no decompression limit and 19 minutes RNT C. 74 minutes no decompression Limit and 24 minutes RNT D. 5 1 minutes no decompression limit and 21 minutes RNT Question 11 Question 16 Using the air RDP, the Equivalent Air Depth Table and the Oxygen Exposure Table: You have just finished your second dive. The last dive yielded pressure group L and your oxygen exposure totals 55%. After a 1 hour, 20 minute surface interval, what the maximum allowable dive time for a dive to 16 metres using is - EA..~x32? A. B. C. D. What are the maximum and contingency oxygen partial pressure limits? A. 1.4 ata and 1.6 ata B. 1.2 ata and 1.4 ata C. 1.2 ata and 1.6 ata D. 0.5 ata and 1.4 ata 162 minutes 79 minutes 198 minutes 55 minutes Question 17 Using the Enriched Air RDPs for EANx36 and EANx32, if your first dive is made using EANx36 to 25 metres for 32 minutes. after a 120 minute surface interval, what are your no decompression limit and RNT for a dive to 20 metres using EANx32? A. 63 minutes no decompression limit and 12 minutes RNT B. 18 minutes no decompression limit and 63 minutes RNT C. 81 minutes no decompression. limit and 14 minutes RNT D. 14 minutes no decompression limit and 81 minutes RNT Question 12 What is the primary hazard of H a F H H G L Q J the oxygen expos ure limits? A. Increased risk of DCI. B. A convulsion underwater.•eading to drowning and a fatal accident. C. An underwater fire or explosion. D. All of the above. 2 Enriched Air Diver Exam VERSION A- METRIC Question 23 Q estion 18 Csing a dive computer with EANx33, you spend 19 minutes above 20 metres, 14 minutes above 16 metres and 22 minutes above 12 metres. What is your oxygen expos ure? -~ Use the EAD formula to determine the exact EAD for 17.3 metres when diving with EANx37: EAD = (1- Oz%) X (D .79 i A. B. C. D. B. 15% c 20% 0 . 25% 12.3 11.8 12.8 13.9 + 10) _ 10 metres metres metres metres Question 19 The signs/symptoms of oxygen toxicity include: A. limb and joint pain, vertigo, poor judgment and laughter. B. vision disturbances, ears ringing, nausea, muscle twitching, irritability and dizziness. C. dry mouth, irregular breathing, uncontrolled shivering and skin itching. D. pale skin, red lips and nail beds, tingling in the fingertips and dehydration. Question 24 Use the oxygen partial pressure formula to determine the exact oxygen partial pressure at 15.5 metres using EANx28: 02 Partial Pressure= A. B. C. D. Question 20 CD+ 10) X 10 02% 1.43 ata 3.23 ata 0.71 ata 0. 78 ata If a diver convulses underwater, the general recom- mendation is that you should handle the situation as you would for any unconscious diver underwater emergency. True False Question 25 Use the Maximum Depth and Contingency Depth Formulas to determine the exact maximum and contingency depths for EANx35: Question 21 Select the true statement: A. You don't need to personally verify enriched air cylinder contents, provided the contents sticker/ tag has been filled out properly. B. Regardless of circumstances, you must personally verify the oxygen content of a filled enriched air cylinder before diving with it. C. Your buddy may verify the oxygen content of your enriched air cylinder if logistics require it. D. None of the above statements are true. Maximum Depth Formula = 14- 10 0 2% Contingency Depth Formula= l2 - 10 0 2% A. B. C. D. Question 22 When you analyze enriched air, the maximum allowable variation in oxygen content is . You should refigure EADs and oxygen exposure, or have the cylinder refilled if the variation is greater. A. 0.1 % B. 0.5% c. 1% D. 10% 3 31 metres and 35 metres 31 metres and 35.7 metres 30 metres and 35 metres 30 metres and 35.7 metres