User manual SCUBAPRO-UWATEC ALADIN AIR Z NITROX

[. . . ] Planning a No-Stop Dive The dive planner will only display depths which lie within the limits of the maximum allowable partial pressure of oxygen (ppO2 max). Planning a Nitrox-dive The dive planner of the Aladin® Air Z Nitrox always plans dives based on the selected oxygen percentage. · Calculate the necessary mixture (Best Mix) for a dive with a given depth. Operation Depth (MOD) Set the desired percentage of oxygen and activate the dive planner as described on page 66/67 of the Air Z manual. [. . . ] Maximum allowable partial pressure of oxygen (ppO2 max) The higher the percentage of oxygen in the used mixture, the sooner you will reach the limit of your allowable dive depth, as defined by your partial pressure of oxygen (ppO2 max) settings. The maximum partial pressure of oxygen can be adjusted with the DataTalk Software between 1. 20 and 1. 95 bar. A ppO2 of more than 1. 6 bar should not be set for safety reasons and is not recommended. The CNS O2%-value and -alarm is not influenced by the selected ppO2 max. Partial pressure of oxygen (ppO2) The set value and the information about the actual ppO2 are not displayed. Surface-mode In the surface-mode the dive computer measures the build-up of micro gas bubbles and the nitrogen saturation als well as the oxygen toxicity of the tissue. The desaturation time is determined either by oxygen- or nitrogen saturation, depending on which gas takes longer. Oxygen saturation <CNS O2 %> is displayed and adjusted until the value declines to 0%. For calculations of the desaturation and No Fly Time it is assumed that the diver inhales air. Wait-mode If you need to change cylinders in this phase, make sure that the new mixture is exactly the same as the one previously used. If you want to dive with another mixture, you must have a 5-minute break at the surface to allow the Aladin® Air Z Nitrox to conclude the dive. Disregarding these rules causes the Aladin® Air Z Nitrox to calculate with wrong mixture data. The kind of air used for diving with compressed air is the same as the normal air of the earth`s atmosphere (78% nitrogen, 21% oxygen and 1% inert gases). However, Nitrox as a breathing gas for diving contains a higher percentage of oxygen than normal air. A higher percentage of oxygen (and therefore a reduced amount of nitrogen) has the advantage of lengthening the nostop phase (or reducing the decompression phase), since less nitrogen is dissolved in the diver`s body during the dive. The higher percentage of oxygen in the Nitrox-mixture can cause additional physiological problems because of the toxic effects of a hightened partial pressure of oxygen (ppO2). When breathing oxygen at a higher partial pressure, two kinds of oxygen toxicity can occur: · CNS damages: Symptoms of intoxication can occur at short notice in the central nervous system (CNS). Such symptoms are: irritation of the respiratory organs, sickness, headache, pulmonary oedema, cramps, unconsciousness. The symptoms can occur at a ppO2 of essentially more than 1 bar and they depend on the length of exposure and on the partial pressure of oxygen. · Damages of the lungs: Symptoms of pulmonary intoxication are long-term effects and may not accur immediately. The symptoms can occur at ppO2 rates from 0. 5 bar and higher and due to long time exposure in the range of several hours/ days. Aladin® Air Z Nitrox considers the short term toxic effects of oxygen (CNS damages) by means of the so called "oxygen- clock". [. . . ] · When diving with Nitrox only use components that have been authorized for diving with Nitrox equipment. · Only use Aladin® Air Z Nitrox with open breathing systems. In semi-closed and closed systems the gas mixture can vary considerably. The calculations may yield results different from those necessary for the actual mixture. [. . . ]