User manual

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ALADIN SQUARE USER MANUAL
2.5.1.2 Switching back to a gas
mixture with lower oxygen
concentration
There may be situations in which you have
to switch back to gas 1 from gas d. This
can happen for instance if you want to
descend again below the MOD for gas d,
or if for instance you have run out of gas
d during the decompression. At this point
you can manually initiate the gas switch by
pressing SEL button. Square will display
the text gas 1, blinking. At this point press
SEL button to confi rm the switch. Square
will display the text gas 1 and adapt the
decompression schedule accordingly.
2.5.1.3 Gas switch not carried out at
the planned depth
If you fail to confi rm the change to gas d
within the 30 seconds of when Square
suggested it, gas d is excluded from
the decompression calculation and the
decompression schedule is adapted
accordingly, basically refl ecting the fact that
you will fi nish the dive using gas 1 only.

NOTE: if after Square has changed
the decompression schedule to re ect
the missed gas switch, you descend
again below the MOD for gas d,
Square reintroduces gas d into the
calculations and the decompression
schedule changes accordingly.
2.5.1.4 Delayed gas switch
You can catch up on a planned gas mixture
switch at any time by selecting the gas
manually. Press SEL button to start the gas
switch procedure. Square will show the text
gas d and its MOD blinking on the display.
This helps you verify that you are performing
a switch to a safe gas. At this point press
SEL button to confi rm the switch. Square
will display the text gas d without blinking
and adapt the decompression schedule
accordingly.
2.5.1.5 Manual gas switch at a depth
deeper than its MOD
There may be situations in which you have
no other choice but to switch to a gas
mixture although you are below the MOD
for that mixture. Square does not prevent
you from doing this, but the MOD alarm will
immediately start. Press SEL button to start
the gas switch procedure. Square will show
the text gas d blinking on the display. This
helps you verify that you are performing a
switch to a safe gas. At this point press SEL
button to confi rm the switch.
2.5.1.6 Submerging below the MOD
after a gas switch
If after having switched to gas d you
inadvertently drop again below the MOD
for that mixture, the MOD alarm will
immediately start. Either switch back to
gas 1, or ascend above the MOD for gas d.
2.6 Warnings and alarms
Square can alert you of potentially
dangerous situations via warnings and
alarms. You can only modify the warning
and alarm settings via PC interface.