20
4 Functions during the dive
III UWATEC
®
Smart dive computers
The prescribed ascent rate must be observed at all times! Exceeding the pre-
scribed ascent rate can lead to microbubbles in the arterial circulation which
can lead to serious injury or death due to decompression sickness.
• In case of an improper ascent TEC may require a decompression stop even
within the no-stop phase because of the danger of microbubble formation.
• The decompression duration necessary for the prevention of microbubbles can
increase massively if the ascent rate is exceeded.
• From great depth a slow ascent may cause heightened saturation of tissues
and an extension of both decompression duration and total ascent time.
At shallow depth, a slow ascent may shorten the decompression duration.
• Display of the ascent rate has the priority over <CNS O
2
>.
Excessive ascent rates for longer periods are entered in the logbook.
Ascent rate
Visual
alarm
Audible alarm
SPEED
SPEED
SPEED
SPEED
S
L
O
W
S
L
O
W
S
L
O
W
S
L
O
W
%
%
%
%
4.7 Partial pressure of oxygen (ppO
2 max
) / Maximum Operating Depth (MOD)
The maximum partial pressure of oxygen ppO
2 max
(default 1.4 bar) determines
the Maximum Operating Depth (MOD). Diving deeper than the MOD will expo-
se the diver to oxygen partial pressures higher than the set maximum level.
The MOD and consequently the ppO
2 max
can be reduced manually at TEC
(->18, setting the gas mixture, point 6).
In addition the maximum allowed ppO
2
can be set by means of SmartTRAK
between 1.0 to 1.95 bar.
The MOD is a function of ppO
2 max
and the mixture used. If during the dive
the MOD is reached or exceeded TEC sends an audible attention message,
the ascent arrow appears and the current depth display starts flashing.
Ascend to a shallower depth in order to diminish the danger of oxygen poiso-
ning.
Change to the gas mixture that is required at this depth by
selecting the appropriate tank symbol.
• The MOD should not be exceeded. Disregarding the warning can lead to
oxygen poisoning.
• ppO
2 max
should not be set higher than 1.6 bar.
%
NO STOP
CNS O
2
%
4 sec
WARNING
WARNING
WARNING
WARNING
