ALADIN ALADIN AIR Z O2, Operating Manual, Page: 15 / 104

15
4 The Calculation Model ZH-L8 ADT
I Uwatec ® Aladin ® Air Z O
2
English
I
bubbles depending on various assumed influences in arterial and venous blood. In normal, slow ascents,
microbubbles form mainly in venous blood. During fast ascents, microbubbles may also form in arterial
blood and in the body‘s tissues as well. If a particular dive profile may result in the creation of micro-
bubbles according to the Aladin
®
Air Z O
2
‘s model, decreased bottom time and/or increased decom-
pression times as well as increased “no fly“ time will be indicated.
• Microbubbles can form if the diver makes too fast an ascent, ignores required decompression stops, or
makes repeated ascents during a dive (yo-yo diving). These microbubbles can form in arterial blood as
well as in the body‘s tissues. If these microbubbles partially impair circulation, the rate of gas diffusion
and saturation tolerance for those tissues immediately surrounding this area of impaired circulation are
changed. If required, both decompression time and RBT will be adjusted in such a way that already
existing microbubbles will stop growing. Increased decompression time will also assist those local areas
of impaired circulation to desaturate with less risk of decompression sickness.
• The calculation of microbubbles results in altered ascent instructions. If microbubbles are assumed to
be present based on the data used by the Aladin ® Air Z O
2
, the ascent rate to the surface is reduced to
7 metres/minute. This will help prevent the formation of microbubbles in the arterial circulation and
minimizes formation of microbubbles in the venous circulation after the dive.
4.2 Advantages
On the first dives following responsible diving procedures, a diver using the Aladin ® Air Z O
2
should never
require decompression stops, although a one to three minute safety stop between 3 and 5 metres is
recommended for every dive. If, however, unplanned circumstances arise during the dive which increase
the risk of decompression sickness, the Aladin
® Air Z O
2
can, if closely followed, reduce the risk by
reducing remaining bottom time and/or increasing decompression time. Some of the more common risk
situations are as follows:
• Repetitive dives, especially those deeper than 20 metres and those with short surface intervals.
• Repetitive diving over the course of several successive days.
• Diving in cold water.
• Diving with increased workloads.
• Yo-yo diving (repeated descents and ascents to the surface during a given dive).