FIG. 22
After the 8 seconds have elapsed, or when the
<Mode> button is pressed, the computer
automatically reverts to the WIN1 display.
If the user attempts to dive while the computer is
in Stop Mode, the profile will nevertheless be
recorded in the logbook.
Stop Mode lasts for 24 hours. The DARWIN can be
released from this condition by clearing the residual
nitrogen memory.
"NITROX" DIVE
Due to the lower percentage of nitrogen in the
breathing mix, diving with oxygen-rich mixtures
carries a lower risk of decompression sickness than
diving with compressed air. However,
the higher oxygen content of the mix exposes the
diver to oxygen toxicity hazards which do not
generally occur in recreational diving with
compressed air. The DARWIN monitors the dive
time and depth and, on the basis of the oxygen
percentage entered in the SET function, provides
indications which allow the diver to remain within
the safety limits for oxygen exposure.
To do a Nitrox dive, it is necessary to choose the
NITROX option in SET1.
The DARWIN handles "Nitrox" dives in a similar
manner to compressed air dives, with the same
phases and procedures for activating DIVE mode.
The only differences between compressed-air and
Nitrox dives concerns the monitoring of critical
"Nitrox" dive parameters, and the display of these
parameters in addition to the normal air dive
parameters (described in the preceding chapter).
The following section describes the critical
"Nitrox" dive parameters monitored by the
DARWIN, and the differences in the data display
layouts.
C
HECKING THE CRITICAL
N
ITROX DIVE
PARAMETERS
O
XYGEN
P
ARTIAL
P
RESSURE
When the diver reaches a depth at which the PPO
2
exceeds the maximum permitted value entered in
the corresponding SET, (from 1.2 to 1.6 ATM), an
alarm condition is triggered indicated by:
Blinking depth indication.
Audible alarm.
The alarm persists until the diver ascends
sufficiently for the oxygen partial pressure to
return within the acceptable limits.
!
WARNING
Before reading the "Nitrox Dive"
chapter, the user is advised to carefully
read the "Air Dive" chapter.
!
WARNING
Correctly setting the percentage of
oxygen in the breathing mix is
indispensable for ensuring correct
readouts of:
- no decompression time remaining;
- decompression stop times;
- alarm for exceeding the maximum
permitted PPO
2
.
!
WARNING
Do not use breathing mixes with % of
O
2
higher than 50%
!
WARNING
Before the dive, check that the Nitrox
dive parameters have been correctly set
up:the percentage of oxygen in the mix
and the partial pressure of oxygen
partial pressure which determines the
maximum permitted depth for the dive.
!
WARNING
This function should only be used by
highly experienced divers. Users who
clear the residual nitrogen memory
cannot use the instrument for repetitive
dives. Do not dive with the DARWIN
after clearing the nitrogen memory if
you have already dived within the
previous 24 hours.
DARWIN DIVE COMPUTER
15
ENGLISH
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Summary of Contents for DARWIN
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