User`s guide

Nemo Air Dive computer
10
the ascent rate returns below the maximum
allowable speed. At the same time as the
audible alarm is triggered, the computer
begins monitoring an “Uncontrolled Ascent.”
An ascent is considered “uncontrolled” when
the diver exceeds the maximum rate for a
stretch equal to at least two thirds of the depth
at which the audible alarm was triggered.
This criterion only applies to alarms triggered
below a depth of 12 m (39 ft). In case of an
uncontrolled ascent, upon surfacing Nemo Air
disables the AIR and EAN functions of DIVE
mode, and will only function as a timer and
depth gauge (BOTTOM TIME).
The stop on the uncontrolled ascent function
can be disabled in SET ALARM mode.
SAFETY STOP
If the maximum depth of a dive exceeds
10 meters, a “SAFETY STOP” is activated for
the ascent. Nemo Air suggests that divers take
a 3-minute safety stop between 2.5 and 6 m
in depth (8 - 19 ft), and will display the words
SAFE STOP. A timer indicates the time needed
to complete the stop (figure 26).
In this mode, the ascent rate is only shown
analogically.
FIG. 26
If the diver moves outside the
above-mentioned depth range, the safety stop
timer is halted. When the diver reenters the
correct depth range, the SAFETY STOP timer
resumes from where it left off.
If the diver returns to a depth below 10 m (32 ft),
the SAFETY STOP timer will ignore the previously
aborted stop and subsequently start counting
down from 3 minutes again. In the case of a
decompression-stop dive, the SAFETY STOP
extends the duration of the decompression
stop at 3 m (10 ft) by an additional 3 minutes,
displaying the information described previously.
DIVE  AIR: SURFACING
When the measured depth is less than 1 m (3 ft),
Nemo Air considers the dive to be suspended
(“SURFACING”) and halts the dive timer. If the
diver does not return below 1.2 m (4 ft) within
the next 3 minutes, the computer considers the
dive to be finished and records its data in the
LOGBOOK. If the diver does re-descend within 3
minutes, the dive continues and the dive timer
resumes from where it left off. Data displayed in
SURFACING mode (figure 27):
FIG. 27
• duration of the dive;
• maximum depth;
• any icons for underwater behavior errors
(omitted stop, uncontrolled ascent);
• tank pressure at the end of the dive;
• average breathing rate for the dive.
 WARNING
If an AIR or EAN dive ends with an
uncontrolled ascent or an omitted stop,
Nemo Air will restrict Dive - AIR and Dive -
EAN modes for 24 hours and will only
allow the BOTTOM TIME operation mode.
 WARNING
Do not fly or travel to high altitudes while
the no-fly indication remains active.
NOTE
The <+> and <-> buttons are disabled in
SURFACING mode.
NOTE
To activate the display backlight, press the
<CENTRAL> button.
DIVE  AIR: SURFACE MODE
When the dive is considered finished, Nemo Air
moves from DIVE mode to TIME mode.
In this situation, the following are displayed
(figure 28):
FIG. 28
• desaturation time (if other than zero);
• the NO FLY icon;
• icons for any errors committed during the
dive (omitted stop, uncontrolled ascent).
Use the <+> and <-> buttons to view:
• no-fly time;
• surf time;
• time, date, temperature.
DIVE  EAN
Because of the lower percentage of nitrogen in
the breathing mix, oxygen-rich mixtures make
it possible to extend the no-decompression
limits, as compared with the same dive with
air. However, the higher oxygen content in
the mix exposes the diver to oxygen toxicity
hazards which are not generally encountered
in recreational dives with compressed air.
In EAN mode, Nemo Air computes oxygen
toxicity on the basis of the dive time, the depth,
and the oxygen percentage setting, providing
indications that enable the diver to remain
within the safe limits for oxygen exposure.
To dive with an EAN mixture, you must first set
EAN mode in SET DIVE.
Nemo Air manages dives with EAN using the
same procedures as dives with AIR.
That means that you will have the same
functions and procedures for selecting the
DIVE mode. The only differences in managing
the two types of dives lie in setting the general
parameters for EAN dives and in the display of
these parameters in addition to the normal AIR
dive parameters, discussed in the preceding
section.
This section will examine the general
parameters for EAN dives monitored by
Nemo Air and the differences in how the data
are displayed.
 WARNING
It is essential to correctly set the oxygen
percentage in the mix to ensure correct
readouts of:
• no-decompression time remaining;
• decompression stop times;
• alarm on exceeding the maximum
permitted PPO
2
.
 WARNING
Before the dive, make sure you have
correctly set up all the EAN dive
parameters: percentage of oxygen in the
mix and limit for the partial pressure of
oxygen, which together determine the
maximum depth of the dive.
 WARNING
The use of oxygen-rich mixes exposes
the diver to different hazards from those
associated with compressed air. The
diver should be aware of these risks and
understand how to avoid them.
 WARNING
Only divers who have the necessary
certification should use Nemo Air for
diving with oxygen-rich mixes (EAN). Lack
of appropriate diver training may result in
serious injury.