16
11.1. SETTING MORE THAN ONE GAS
The characteristics of the gases must be
entered in the computer before the dive. Itwill
then be your responsibility to tell Genius which
gas is currently being used during the various
phases of the dive.
NOTE
- If you dive using just one gas, select G1
and deselect the other two.
- For dives with two gases, select G1 and
G2 and deselect the third.
- When enabling G2 and G3, you must first
define G2 and then G3.
- You cannot activate G3 without first
having activated G2.
- G2 cannot have an oxygen percentage
higher than G3.
- If you set G2 to OFF, G3 will
automatically be set to OFF also.
- The MOD for G2 and G3 is the switch
depth for the corresponding gas. This
is what Genius uses for its calculation,
alarms and suggested switch points.
- Setting a tank to OFF does not affect
the pairing of the corresponding tank
module.
To use multiple gases, you will need to enable
the gases and set the oxygen percentage
and the ppO
2
max for each one, as described
in Figure 33. Keep in mind that the MOD for
G2 and G3 is the depth at which Genius will
prompt you to perform the gas switch (see
section 11.2 below).
11.2. SWITCHING GAS
During Nitrox dives with the gas switching
function enabled, the third button from the left
has two functions, indicated by a double icon:
• Press: scrolls through the sequence of
information to the right of the dive time
.
• Press and hold: displays the gas switch
screen
.
Genius always begins the dive with G1,
which has the lowest percentage of oxygen.
When during the ascent you reach the depth
corresponding to the MOD of G2, Genius sounds
an audible signal and displays the message
SWITCH TO GAS G2 below the top row (Fig.
34). The left button now has label NO while
the second and the third button have label OK.
Press or press and hold either of the OK buttons
to perform the switch, at which point Genius
shortly displays the message GAS SWITCH OK;
press or press and hold the NO button to stay on
the current gas, at which point Genius shortly
displays the message GAS NOT SWITCHED. If
you don’t perform any action within 30 seconds,
Genius shows GAS NOT SWITCHED and returns
to the normal display. If set to PREDICTIVE =
ON and the gas was not switched, Genius will
show the message EXCLUDING GAS G2 prior
to changing the decompression calculation to
reflect the exclusion of G2.
If you drop again below the MOD for G2, Genius
will show the message INCLUDING GAS
G2 AGAIN and changes the decompression
calculation accordingly.
NOTE
The same process is repeated when you
approach the MOD for G3 with the message
SWITCH TO GAS G3
You can always perform a manual switch, by
pressing and holding
. This will make the gas
switch screen appear, which shows all active
gases (Fig. 35).
NOTE
You can reach this screen at any time
during the dive, for instance to check on
the tank pressure and the planned switch
point of G2 and G3.
Press to scroll through the available gases,
then press to activate it. The decompression
calculation will reflect the switch in breathing
gas. In addition, the display will now show
the symbol of the new gas and its oxygen
concentration. In profile view, the area below
the MOD of the deco gas is depicted in red.
NOTE
- You can select another gas using , if
permitted at that depth.
- You can exit this mode without changing
the gas by pressing
.
- If there is only one gas set, the computer
will not enter this menu.
11.3. SPECIAL SITUATIONS
11.3.1. SWITCHING BACK TO A GAS
MIXTURE WITH LOWER OXYGEN
CONCENTRATION
There may be situations in which you have
to switch back to a gas with lower oxygen
concentration than what you are currently
breathing. This can happen for instance if you
want to descend deeper than the MOD for the
current gas, or if for instance you have run out
of gas in G3 during the decompression. To do
so, simply press and hold
to call up the gas
switch screen. Use to choose another gas,
then press to activate it. The decompression
calculation will reflect the switch in breathing
gas.
11.3.2. SUBMERGING BELOW THE MOD
AFTER A GAS SWITCH
If after having switched to a gas mixture with a
higher oxygen concentration you inadvertently
drop again below the MOD for that mixture,
the MOD alarm will immediately go off. Either
switch back to a gas mixture suited for that
depth, or ascend above the MOD for the gas
mixture you are breathing from.
11.3.3. RGT WHEN DIVING WITH MORE THAN
ONE GAS MIXTURE
Genius determines the RGT based on your
breathing pattern, the tank pressure for the
gas you are currently breathing, and the
decompression time calculated for that gas
only. It does not account for tanks other than
what you are currently breathing from, hence
your actual autonomy may be higher. For this
reason when diving with more than one gas
mixture the RGT = 3 min is a soft warning and
not an alarm.
11.3.4. LOGBOOK FOR DIVES WITH MORE
THAN ONE GAS MIXTURE
For dives carried out with more than one gas
mixture, Genius adds information on oxygen
concentration, initial, final and differential
pressure for all gases used. On the dive profile,
switch points are shown on the time line.
11.4. DIVING WITH MORE THAN
ONE GAS MIXTURE TRIMIX
OR HELIOX
Genius allows you to set up to 5 gases in which
in addition to the oxygen percentage you can
also set the helium percentage. In the tissue
saturation graph you will see bars for the
nitrogen partial pressure and for the helium
partial pressure. Everything else is the same as
with multigas nitrox diving with the addition of
OTUs (Oxygen Toxicity Units) in the
sequence.
• 12. BOTTOM TIMER MODE
When Genius is set to BOTTOM TIMER mode,
it will only monitor depth, time, tank pressure
and temperature, and will not carry out any
decompression calculation. You can only
switch to bottom timer mode if the computer is
completely desaturated. All audible and visual
alarms, other than the low battery alarm, are
turned off.
WARNING
Dives in gauge mode are performed at your
own risk. After a dive in bottom timer mode
you must wait at least 24 hours before
diving using a decompression computer.
During a dive in gauge mode, the following
information is displayed (Fig. 36):
- current depth
- max depth
- average depth
- stopwatch
- dive time
- temperature
- time of day
- battery status
- tank pressure
- in case of an ascent: ascent speed (in m/min
or ft/min).
The stop watch is reset by means of
. Upon
pressing and holding the same button, the gas
switch display is called up. The only result of
switching gas mixtures in bottom timer mode
is that the pressure of the newly chosen tank is
displayed instead of the current one.
To Next Page
Loading...