SUUNTO HELO2 - Manual (Page 32)

MIXED GAS DIVE MODE ACTIVATION,
MAXIMUM OPERATIONAL DEPTH BASED ON
SET O
2
% (14%), HE
2
% (32%), AND PO
2
(1.4) IS
83.3 M.
If set to MIXED GAS mode, the Suunto HelO
2
will additionally show on the alternative
display:
•
the oxygen percentage, labeled O
2
%
• the helium percentage, labeled He%
• the set oxygen partial pressure limit, labeled PO
2
• the current oxygen toxicity exposure, labeled OLF
• maximum depth
• current time
• water temperature
• dive time
• tank pressure
UP BUTTON
TOGGLES
BETWEEN PO
2
,
OLF, DIVE TIME
AND WATER
TEMPERATURE.
DOWN BUTTON
TOGGLES
BETWEEN O
2
:HE,
MAXIMUM DEPTH
TANK PRESSURE
AND CURRENT
TIME.
6.2.3. Oxygen limit fraction (OLF)
If set to MIXED GAS mode, in addition to tracking the diver's exposure to inert gas, the
instrument tracks the exposure to oxygen. These calculations are treated as entirely sep-
arate functions.
The dive computer calculates separately for Central Nervous System oxygen toxicity (CNS)
and Pulmonary Oxygen toxicity, the latter measured by the addition of Oxygen Toxicity
Units (OTU). Both fractions are scaled so that the maximum tolerated exposure for each
is expressed as 100%.
The Oxygen Limit Fraction (OLF) displays only the value of the higher of the two calcula-
tions. The oxygen toxicity calculations are based on the factors listed in Section 10.3.
Oxygen exposure .
6.2.4. Gas change and multiple breathing gas mixes
The Suunto HelO
2
allows gas changes to enabled gas mixes during the dive.When the
maximum operating depth allows for a gas change, the dive computer prompts you to
change the gas. When PO
2
permits better decompression gas to be used, the dive computer
prompts it automatically if it is set as primary. Gas changes are made by following the
procedure below:
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