Cressi Archimede II, User Manual

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3.2. - HYPER-OXYGENATED (NITROX) MIXTURES
DIVE
3.2.1. - Before a Nitrox dive.
m
DANGER: the use of the computer with hyper-oxyge-
nated (Nitrox) mixtures is exclusively intended for divers
who have attended a full training course on the use of
such mixtures.
The Nitrox program for Archimedes II computer allows
making saturation and de-saturation computations for a dive
by using up to two different nitrox mixtures and is switched on
any time the parameters of program the primary
mixture FO2 on Mix1=21% and second mixture Mix2=off, are
changed. In this case the display will show (Nitrox) icon (pictu-
re 12) which will stay on during the dive and until Archimedes
II
remains set on Nitrox parameters.
Once Nitrox program is on, it is necessary to set Archimedes
II
computer with the exact values of oxygen percentage (FO2)
contained in the cylinders to be used during the dive, after
having analyzed their content, so the computer is able to adapt
its computing algorithm according to the new set parameters.
WARNING: Archimedes II computer always keeps
program switched on for air dives, until the diver
sets it for the use with Nitrox mixtures (chapter 2.3.1– Dive
parameters setting)
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DANGER: Do not dive with cylinders containing Nitrox
mixtures without checking their oxygen percentage.
WARNING: Before diving, always check the oxygen per-
centage of the mixture(s) set on the computer. This is done
on surface by depressing button A ( ) which allows visua-
lization of the previously set parameters.
WARNING: Under the same dive conditions, a Nitrox mix-
ture requires longer no decompression times than air. It is
recommended to comply with the maximum depth allowed
by the selected Nitrox mixture.
Related topics:
• 2.3.1. - parameters setting.
• 2.3.3. - Rapid visualization of set data.
• 3.3.
- Nitrox parameters setting.
• 3.3.3. - Mixture changing by diving.
• 3.3.4. - CNS toxicity display.
• 3.3.5. - PO2 alarm.
3.3. - Nitrox parameters setting.
3.3.1. - Partial pressure setting (PO2).
Archimedes II is set at the factory on a basic PO2 value of 1.4
bar for both mixtures of Nitrox and air dives, in order to gua-
rantee the maximum safety during dives.
It is possible to modify the PO2 setting on values between 1.0
bar and 1.6 bar. Should you elect to increase the dive’s margin
of safety, it is possible to set PO2 on lower values, down to a
minimum of 1.0 bar. It is explained in paragraph 2.3. how to
carry out the selection of values. To do so, depress the central
button B (Mode) to the ( ) menu, shown in picture 3, and
the parameters will be modified according to the following
scheme: by depressing button A ( ) it is possible to select, in
Archimede II 2006 3-11-2006 10:17 Pagina 174