






Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
Nitrox certification Questions and Answers
Typology: Exams
1 / 10
This page cannot be seen from the preview
Don't miss anything!
A mixture of nitrogen and oxygen in which the percentage of oxygen is greater than that found in air is generally called: - ANSWER-all Additional steps Nitrox divers can take to help avoid oxygen toxicity include all of the following except: - ANSWER-Never exceed a PO2 of 2.0. Decompression diving involves more risk than no-decompression diving, and without the proper precautions can become extremely hazardous. - ANSWER-true Decompression sickness usually occurs when you have an excess amount of __________ in your body and you ________ too quickly. - ANSWER-Nitrogen, asend Dive computers work by: - ANSWER-Calculating the approximate amount of excess nitrogen present in your body, based on factors such as depth and time. During any 24-hour period, you can be exposed to a Nitrox mixture at its Maximum Operating Depth (MOD) for up to: - ANSWER-150 Min EAN32 is a good choice for Nitrox diving because it provides a good combination of safety and extended bottom time. - ANSWER-True f you do not set your dive computer's FO2 prior to every dive: - ANSWER-all First aid for decompression sickness can include: - ANSWER-Treating for shock., Administering pure oxygen. How can a dive computer help you avoid decompression sickness? - ANSWER--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. If you go too deep or stay too long, you may not be able to make a direct ascent to the surface without substantially increasing your risk of decompression sickness. - ANSWER-True It is important for team members to be use the same Nitrox mixture so that they will share a common MOD. - ANSWER-true Nitrox is still relatively rare at most dive destinations and liveaboards. - ANSWER-false Once a diver suspected of suffering from decompression has been transported to a medical facility, proper treatment will primarily involve recompression in a hyperbaric chamber. - ANSWER-True
Oxygen toxicity is a physiological reaction of your body that occurs when you are exposed to breathing mixtures containing: - ANSWER-High partial pressures of oxygen, Lower partial pressures of oxygen for extended periods Regulators that will be exposed to oxygen concentrations of less than 40 percent need no special preparation unless required by manufacturer's specifications or local laws/regulations. - ANSWER-True State how long, in any 24-hour period, you can be exposed to a Nitrox mixture at its Maximum Operating Depth (MOD)? - ANSWER--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. The air we normally breathe consists primarily of: - ANSWER-Nitrogen + Oxygen The maximum partial pressure of oxygen (PO2) we use in Nitrox diving is: - ANSWER- none The maximum percentage of oxygen that sport divers use in a Nitrox mixture is: - ANSWER-40% The maximum recommended depth for using 100 percent oxygen is 6 m/20 ft. - ANSWER-True The minimum surface interval for Nitrox diving is 30 minutes; however, 60 minutes is preferred. - ANSWER-True The MOD for EAN32 is 30 m/99 ft. - ANSWER-False The most common symptoms of decompression sickness can include, but are not limited to, pain in the joints, numbness, paralysis, loss of balance, muscle weakness, and impaired thinking. - ANSWER-True The primary benefits of using Nitrox include longer bottom times and shorter surface intervals. - ANSWER-True The primary risk associated with Nitrox diving (as opposed to diving air) is carbon monoxide (CO) poisoning. - ANSWER-False The steps to follow when analyzing Nitrox cylinder content include: - ANSWER-all The term blender refers to an individual who is qualified to: - ANSWER-create the Nitrox used to fill scuba cylinders.
use special o-rings and other Nitrox compatible components including lubricants. The real value of a dedicated Nitrox regulator is in situations where levels of oxygen higher than 40 percent will be used. markings are yellow and green What are the common terms divers may use when referring to Nitrox? - ANSWER--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 key difference between semi-closed circuit and fully-closed circuit rebreathers? - ANSWER-The semi-closed circuit rebreather is designed to re-circulate most of each breath you take, by removing the carbon dioxide (CO2) from your exhaled breath and adding oxygen as it is consumed. fully-closed circuit models do not release any breathing gas bubbles into the water, except during the ascent at the end of the dive. They work in a similar manner to the semi-closed circuit rebreather. What are the key differences between the SDI Easy Nitrox Diver course and the TDI Advanced Nitrox Diver course? - ANSWER- What are the minimum and preferred surface intervals for Nitrox diving? - ANSWER- min,60 preferred What are the most common symptoms of decompression sickness? - ANSWER--The most common symptoms include, but are not limited to, pain in the joints, numbness, paralysis, loss of balance, muscle weakness, and impaired thinking. What are the primary component gasses found in air, and the percentage of the total gas mixture each gas represents? - ANSWER-- However, unlike air which normally contains approximately 79 percent nitrogen and 21 percent oxygen, Nitrox contains a higher percentage of oxygen. What are the steps to follow when analyzing Nitrox cylinder content? - ANSWER- calibrate, analyze, label Begin by connecting your analyzer system to its calibration source, be that a cylinder of pure oxygen, premixed Nitrox or air. Oxygen sensors are not only sensitive to oxygen, they can also be affected by the presence of moisture, changes in temperature, sensor age and other factors. Therefore, every time you use an oxygen analyzer, you must calibrate its display against a reference gas whose FO2 is unequivocal. This can be pure air, oxygen or, lacking these a Nitrox mixture with an FO2 that has been verified by at least two other analyzers.
Most Nitrox divers use pure air as a reference gas, as its FO2 is unequivocal and, being closer to the FO2 of the mixture being analyzed, the margin for error is less than it would be if using pure oxygen as a reference gas. Turn the calibration source on. If using an oxygen regulator or other means of adjusting gas flow, adjust the flow rate to that specified by the analyzer manufacturer. Fixed rate meters generally restrict gas flow to a rate of approximately two litres per minute; this is an acceptable rate for most analyzers. Once the gas is flowing, and has had the opportunity to displace the air previously in the line, adjust the calibration dial so that it reads either 100.0 percent for oxygen, 20. percent for air or the correct percentage for another calibration source, if used. (The calibration dial may be very sensitive; getting the setting within +/- 0.1 percent of the target is generally considered adequate.) Allow the calibration gas to flow for at least another 30 seconds. Make certain there are no substantial variations in the FO2 reading during this time. If you will be analyzing several cylinders in succession, you only need to calibrate your analyzer once. Disconnect the analyzer set-up from the calibration source. Reconnect it to th What are the two gases that most Nitrox diving computers take into consideration when computing your allowable bottom time? - ANSWER-Nitrogen and oxygen. What are the two gases that most Nitrox diving computers take into consideration when computing your allowable bottom time? - ANSWER-you may hear people talk about CNS (Central Nervous System) oxygen limits, OTUs (Oxygen Tolerance Units), OLF (Oxygen Limit Fraction), OTLs (Oxygen Time Limits), or use other terminology. At Scuba Diving International we prefer to use the term Oxygen Time Limit when we are referring to the maximum exposure you can have to enriched oxygen mixtures underwater What are the two most important pieces of information that will appear on a Nitrox fill tag or label? - ANSWER-Any tank used for Nitrox diving must also have a tag or label attached to it where the exact Nitrox mixture used in the tank (FO2) and its MOD can be read What are the two most important pieces of information that will appear on a Nitrox fill tag or label? - ANSWER-Fo2 + MOD What are the two primary benefits divers enjoy by using Nitrox? - ANSWER--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.
continuously on it. This tape makes it quick and easy to spot a Nitrox bottle in a group of tanks. What does term Nitrox mean? - ANSWER--Nitrox a mix of nitrogen and oxygen just like air. What does the term blender mean, as it applies to Nitrox diving? - ANSWER-To the Nitrox diver, the blender is an important person who holds the key to your Nitrox diving. Without a properly trained blender, you wont be able to dive Nitrox with any degree of confidence. What does the term decompression stop mean? - ANSWER--During these decompression stops, the excess nitrogen in your body is carried back to the lungs where you exhale it each time you breathe. What does the term EAN32 mean? - ANSWER-That mixture is 68 percent nitrogen and 32 percent oxygen (EAN32). What does the term MOD mean? How is it used in Nitrox diving? - ANSWER--The higher the percentage of oxygen used in the mixture, the shallower the Maximum Operating Depth or MOD is for a particular mixture. -shallower depth, planned diving, longer time What does the term oxygen toxicity mean? - ANSWER--Oxygen toxicity (also referred to as oxygen poisoning) is a 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. It can be more easily understood as a condition that occurs when the diver breathes a mixture of gas that allows the PO2 to exceed 1.6 by going to deep or exceeding the time limit at a lower PO2. Therefore you as a diver must set and follow your MOD for every mix on every dive. -Pulmonary Oxygen Toxicity can develop when you are exposed to elevated levels of oxygen over long periods of time. However the length of time involved is well beyond that of most recreational dives. Thus it poses no real risk to sport divers. -Central Nervous System (CNS) Oxygen Toxicity is of greater concern. This is because all a diver must do is violate the Maximum Operating Depth (MOD) for a particular mix causing the P02 to rise above 1.6 and the chances for a CNS hit increase exponentially. What does the term technical diving refer to? - ANSWER-Technical diving is a type of recreational diving that goes beyond sport diving limits. Typically, it requires additional specialized training, planning techniques, and equipment. It provides the diver with capabilities well beyond the limitations of sport diving. What is an oxygen analyzer? - ANSWER-An electronic device used to measure the percentage of oxygen in a gas mixture.
What is an oxygen analyzer? - ANSWER-Oxygen analyzers are electronic devices that are used to measure the percentage of oxygen in a gas mixture. They run on batteries and most are equipped with a sensor that measures the percentage of oxygen in a gas mixture. What is the acceptable range of accuracy blenders must adhere to when asked to supply a Nitrox mixture with a particular FO2? - ANSWER-within 1 percent What is the FO2 setting most dive computers default to? - ANSWER-In most cases, the default setting for the percentage of oxygen will be 21 percent. The default setting for PO2 is frequently 1.4. If you fail to change these settings you will not be getting the full benefit of the capabilities of your computer and Nitrox. What is the function of a fill station log? - ANSWER- What is the key reason why, when available, technical divers generally prefer Trimix for dives past 40 m/132 ft? - ANSWER-The concept behind Trimix diving is that by replacing most of the nitrogen in the breathing gas with helium, you will be affected less by nitrogen narcosis than you would be using regular air. What is the maximum partial pressure of oxygen (PO2) we use in Nitrox diving? - ANSWER-1. What is the maximum percentage of oxygen that sport divers use in a Nitrox mixture? - ANSWER-or sport diving, we limit the range of Nitrox mixtures of up to EAN40 that work within the range of sport diving depths What is the maximum recommended depth for using 100 percent oxygen? - ANSWER- During World War II, military divers found that they could dive with 100 percent oxygen, but only use this mixture down to a depth of 6 m/20 ft What is the minimum concentration of oxygen required to maintain consciousness at sea level? - ANSWER-16% What is the minimum concentration of oxygen required to maintain consciousness at sea level? - ANSWER-On the surface, you can breathe gas mixtures containing as little as 16 percent oxygen and still maintain consciousness. What is the MOD for EAN32? - ANSWER-The reason EAN32 is considered the optimum Nitrox mixture is because it is the most oxygen rich mixture that you can use up to the maximum recommended sport diving depth limit of 40 m/132 ft. What is the most important setting that must be made to your Nitrox computer before every dive? - ANSWER-FO
Which of the following is not a factor that may increase a diver's susceptibility to oxygen toxicity? - ANSWER-Vitamin C deficiency. Which of the following statements best describes a decompression stop? - ANSWER- Pausing at a fixed depth for a specified period of time to allow excess nitrogen to exit your body more slowly. Why it is important for team members to use the same Nitrox mixture? - ANSWER- Why may you need additional thermal protection for Nitrox diving? - ANSWER-To compensate for heat loss on longer dives. Why may you need additional thermal protection for Nitrox diving? - ANSWER-Whether you dive in the tropics or in colder waters, the extended bottom times provided by Nitrox will usually necessitate more thermal protection/insulation than you might ordinarily wear You ask a Nitrox blender to fill your cylinders with EAN30, but they analyze at 32 percent. You should not be concerned, as this is within the acceptable range of accuracy for Nitrox fills. - ANSWER-False Your SDI Nitrox Diver certification allows you to use Nitrox mixtures whose oxygen content ranges as high as 40 percent (EAN40)? - ANSWER-True Your signature in the gas fill log indicates:That you take responsibility for the Nitrox that has been delivered to you, and that you are satisfied that your cylinders have been filled properly. - ANSWER-true