to be understated and will affect decompression calculations. If you want to adjust the
computer to provide more conservative calculations, use the personal adjustment
feature to affect decompression calculations, or reduce the PO
2
setting to affect oxygen
exposure according to the entered O
2
% and PO
2
values. Calculations based on nitrox
use result in longer no-decompression times and shallower maximum depths than
diving with air.
As a safety precaution, the oxygen calculations in the computer are made with an
oxygen percentage of 1% + set O
2
%.
When the dive computer is set in NITROX mode, the Dive Planning mode calculates
using the O
2
% and PO
2
values that are currently in the computer.
To set the nitrox mixes, refer to Section 5.7.3. Setting the nitrox values .
Default nitrox settings
In the NITROX mode, the Suunto Cobra3 allows you to set 1 or 2 nitrox mixes contain-
ing 21–99% oxygen.
In the NITROX mode, the default setting for Mix1 is standard air (21% O
2
). It remains
in this setting until the O
2
% is adjusted to any other percentage of oxygen (22%–99%).
The default setting for maximum oxygen partial pressure is 1.4 bar, however you are
able to set it in the range of 0.5–1.6 bar.
Mix2 is set to OFF by default. To set Mix2, refer to Section 6.2.4. Gas change and
multiple breathing gas mixes. Oxygen percentages and maximum oxygen partial
pressures for Mix2 are stored permanently.
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