SUUNTO Cobra2 - Manual (Page 45)

• Life expectancy at 20°C/68°F:
•
0 dives/y - 3 years
• 100 dives/year – 2 years
• 300 dives/year – 1.5 years
The following conditions have an effect on the expected battery lifetime:
•
The length of the dives
• The conditions in which the unit is operated and stored (e.g. temperature/cold
conditions). Below 10°C/50°F the expected battery lifetime is about 50-75% of that at
20°C/68°F
• The use of the backlight and audible alarms
• The use of the compass
• The quality of the battery. (Some lithium batteries may exhaust unexpectedly, which
cannot be tested in advance)
• The time the dive computer has been stored until it gets to the customer. (The battery
is installed in the unit at the factory)
NOTE Low temperature or an internal oxidation of the battery may activate
the battery warning even though the battery has enough capacity. In
this case, the warning usually disappears when the DIVE mode is
activated again.
9.2. RGBM
The Suunto Reduced Gradient Bubble Model (RGBM) is a modern algorithm for predicting
both dissolved and free gas in the tissues and blood of divers. It was developed in co-
operation between Suunto and Bruce R. Wienke BSc, MSc, PhD. It is based on both
laboratory experiments and diving data, including data from DAN.
It is a significant advance on the classical Haldane models, which do not predict free gas
(microbubbles). The advantage of Suunto RGBM is additional safety through its ability to
adapt to a wide variety of situations. Suunto RGBM addresses a number of diving
circumstances outside the range of dissolved-gas-only models by:
•
Monitoring continuous multiday diving
• Computing closely spaced repetitive diving
• Reacting to a dive deeper than the previous dive
• Adapting to rapid ascents which produce high microbubble (silent-bubble) build-up
• Incorporating consistency with real physical laws for gas kinetics
9.2.1. Suunto RGBM adaptive decompression
The Suunto RGBM algorithm adapts its predictions of both the effects of microbubble
build-up and adverse dive profiles in the current dive series. It also changes these
calculations according to the personal adjustment you select.
The pattern and speed of decompression at the surface is adjusted according to
microbubble influence.
On repetitive dives, adjustment may also be applied to the maximum allowable nitrogen
overpressure in each theoretical tissue group.
Depending on the circumstances, Suunto RGBM will adapt the decompression obligations
by doing any or all of the following:
•
Reducing No-decompression Stop dive times
• Adding Mandatory Safety Stops
• Increasing Decompression Stop times
• Advising an extended surface interval (Diver Attention symbol)
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