Oxygen Limit Fraction (Olf); Diving In Free Mode (Divefree) - Suunto D4 User Manual

6.2.3. Oxygen limit fraction (OLF)

If set to NITROX mode, in addition to tracking the diver's exposure to nitrogen, the
instrument tracks the exposure to oxygen. 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 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 cal-
culations. The oxygen toxicity calculations are based on the factors listed in Sec-
tion 10.3. Oxygen exposure .

6.3. Diving in FREE mode (DIVEfree)

If set to FREE mode, the dive computer can be used as a free diving instrument.
In the FREE mode, the total dive time is always displayed in minutes and seconds
(mm:ss) in the center window.
UP BUTTON
TOGGLES
BETWEEN PO ,
2
OLF, DIVE TIME
AND WATER
TEMPERATURE.
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