Oxygen Limit Fraction (Olf); Gas Change, Multiple Breathing Gas Mixes - Suunto VYTEC DS Instruction Manual

After fi ve seconds the display will automatically
revert to the original display.
3.4.3. Oxygen Limit Fraction
(OLF)
In addition to tracking the diver's exposure to
nitrogen, the instrument tracks the exposure to
oxygen, if set to Nitrox mode. These calculations
are treated as entirely separate functions.
The dive computer calculates separately for
Central Nervous System oxygen toxicity (CNS)
and Pulmonary Oxygen toxicity, the latter mea-
sured by the addition of Oxygen Toxicity Units
(OTU). Both fractions are scaled so that the
maximum tolerated ex posure for each is ex-
pressed as 100%.
The Oxygen Limit Fraction (OLF) has 11 seg-
ments, each representing 10%. The OLF bar
graph displays only the value of the higher of
the two calculations. When the OTU value
meets and exceeds the CNS value then in ad-
dition to displaying its percentage the lowest
segment blinks to indicate that the value
shown relates to OTU. The oxygen toxicity
calculations are based on the factors listed in
section 6.3. "Oxygen Exposure".
3.4.4. Gas Change, Multiple
Breathing Gas Mixes
The Vytec has as a special feature the possibil-
ity to set two additional nitrox mixes to be used
during the dive. This feature can be activated
by setting the MIX2 and/or MIX3 "ON" and
entering other parameters in the same way
as on the primary gas (See chapter 4.3.1.4
Nitrox/Oxygen settings). Mix 2 and 3 settings
are held until you change them (they will not
return to default settings automatically). Cyl-
inder pressure data is available for one wire-
less transmitter only. A dive is always started
with MIX1, during the dive the Vytec lets you
change to any enabled mix, which is within the
Fig. 3.25. Alternative
display. Pressing TIME
button displays current
time, maximum depth,
temperature, CBT and
O2%, if Air Time is less
than 30 minutes.
Fig. 3.26. The lowest bar
graph blinks to indicate
that the OLF value shown
relates to OTU.
Fig. 3.27 Changing gas
mix. Current gas mix is MIX1
(21%). Scroll though enabled
mixes by pressing PLAN or
TIME button. Select new
mix by pressing MODE (OK)
button.
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