47
ENGLISH
Diving with 2 or 3 gas mixtures
NOTE:
• The time to reset the O
2
% mix to air can be set with Dive.Log between 1 hour and 48 hours or
to “no reset” (default).
After the reset, the oxygen fraction of gas 1 is set to 21%, the oxygen fractions of gas 2 and
gas d are set to “– – O
2
%” (single gas dive).
Switching between single-gas and two-gas diving
If gas 2 / gas d is not going to be used during the next dive you can either set it to “– – O
2
%” (->22,
point 2) or you can turn off the deco gas option in SET 1. When you turn off the deco gas option in SET
1, the setting in the Gas 2 O2 / Gas d O
2
menu remains but Subgear XP-3H calculates the dive using
gas 1 only.
If the deco gas option is turned off, the Gas 2 O2 / Gas d O
2
menu will display OFF in the lower left corner
(instead of an MOD) and the ppO
2
setting will not appear.
Functions during a dive with 2 or 3 gas mixtures
WARNING
Diving with more than one gas mixture represents a much higher risk than diving with a single mixture, and
mistakes by the diver may lead to serious injury or death.
During dives with several gas mixtures, always make sure you are breathing from the tank you intended to breath
from. Mark all your tanks and regulators, so they can under no circumstances be mixed up! Before every dive
and after changing a tank, make sure that each gas mixture is set to the correct value for the corresponding tank.
Predictive decompression prognosis
The calculation of decompression data is based on the assumption that the change(s) of gas mixture(s)
will be performed at the previously selected switch depth(s) (MOD gas 2 /gas d). If a diver ignores a
required change or changes the mixture belatedly, Subgear XP-3H will readjust the decompression
calculation accordingly. In case of an ignored switch the dive computer will then base its calculations on
the assumption that the diver will ascend to the surface with gas 1.
