What is the FO2 setting most dive computers default to? 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 most important setting that must be made to your Nitrox computer before every dive?
The most important setting that must be made to your Nitrox computer before every dive is the FO2 of your breathing mixture. … An oxygen analyzer is an electronic device used to measure the percentage of oxygen in a gas mixture.
What is FO2 in diving?
A diver’s oxygen exposure is like a burning candle. … This is commonly referred to as the partial pressure of oxygen or PPO2. PPO2 is calculated by multiplying the fraction of oxygen (FO2) in a scuba tank by the pressure at depth in atmospheres absolute (PATA).
What are the two gases that a Nitrox diving computer takes into consideration when computing your allowable bottom time?
The two gases that a Nitrox diving computer takes into consideration when computing your allowable bottom time are nitrous oxide and carbon monoxide.
At what depth does air become toxic?
The higher the Fio2 the greater the risk. Breathing air containing 21% oxygen risks acute oxygen toxicity at depths greater than 66 m; breathing 100% oxygen there is a risk of convulsion at only 6 m.
Is Nitrox better than air?
Breathing air which is enriched with more oxygen reduces the amount of nitrogen and therefore reduces the risk. A dive on Nitrox will be much safer than the same dive profile on air. … Nitrox divers are able to extend their NDL because the gas that they are breathing has less nitrogen than a diver’s on air.
How deep you can dive with Nitrox?
The two most common recreational diving nitrox mixes contain 32% and 36% oxygen, which have maximum operating depths (MODs) of 34 metres (112 ft) and 29 metres (95 ft) respectively when limited to a maximum partial pressure of oxygen of 1.4 bar (140 kPa).
How is PPO2 calculated?
Dalton’s Law is represented mathematically as PPO2=Fg x P (partial pressure of oxygen = fraction of oxygen x Pressure). The first step is to convert our dive depth to atmospheres (ATA). To convert we merely divide the depth by 33 feet (for salt water) and we add 1 ATA to account for the pressure at the surface.
What is an advantage of Nitrox diving?
The Nitrox we use in recreational scuba diving is between 21 and 40% oxygen, and contains a lower percentage of nitrogen than air. This reduced percentage of nitrogen in recreational Nitrox allows divers to extend their no decompression limits or dive time by reducing the amount of nitrogen absorbed.
How do you calculate Nitrox?
How deep can I safely dive with this nitrox ? We get 1.4 / 0.32 = P 1.4 is the partial pressure of oxygen divided by 0.32 the % oxygen = P the pressure. we get 1.4 / 0.36 = P 1.4 is the partial pressure of oxygen divided by 0.36 the % oxygen = P the pressure.
How do you calculate maximum operating depth?
The formula simply divides the absolute partial pressure of oxygen which can be tolerated (expressed in atmospheres or bar) by the fraction of oxygen in the breathing gas, to calculate the absolute pressure at which the mix can be breathed.
What are two equipment items that do not need to be cleaned for oxygen service?
What are two equipment items that do not need to be cleaned for oxygen service? Equipment that is exposed to low pressure oxygen, such as buoyancy compensators and their low pressure inflators and dry suit inflation valves do not need to be cleaned or lubricated for oxygen service.
Which of the following statements best describes a decompression stop?
Which of the following statements best describes a decompression stop? Pausing at a fixed depth for a specified period of time to allow excess nitrogen to exit your body more slowly. Decompression diving involves more risk than no-decompression diving, and without the proper precautions can become extremely hazardous.
Why is air toxic at depth?
On the surface the partial pressure of O2 in air is 0.21 ATA (0.21 * 1.0 ATA = 0.21 ATA). … The narcotic effect of nitrogen causes air divers to limit their depth to a maximum of 130 fsw (40 msw). At that depth breathing air, the pO2 is just over 1.0 ATA, too low to worry about CNS toxicity.
Why is breathing pure oxygen bad?
Oxygen radicals harm the fats, protein and DNA in your body. This damages your eyes so you can’t see properly, and your lungs, so you can’t breathe normally. So breathing pure oxygen is quite dangerous.
What is the most serious sign of CNS toxicity?
The first and most serious sign of CNS oxygen toxicity is often a grand-mal type convulsion. There are many other signs and symptoms of oxygen toxicity but there is no consistent warning that a seizure is about to occur.