Suunto HELO2 Scuba Diving Equipment User Manual


 
Helium halftimes:1, 2, 3.5, 7.5, 15, 30, 45, 90, 181 minutes (on gassing). The off
gassing halftimes are slowed down.
Reduced gradient (variable) "M" values based on diving habit and dive violations. The
"M" values are tracked up to 100 hours after a dive
The EAN and oxygen exposure calculations are based on recommendations by R.W.
Hamilton, PhD and currently accepted exposure time limit tables and principles
Battery:
One 3 V lithium battery: CR 2450
Battery storage time (shelf life): Up to three years
Replacement: Every three years, or more often depending on dive activity
Life expectancy at 20°C/68°F:
100 dives/year –>1 year
Transmitter:
One 3V lithium battery: 1/2AA (K5546) and O-ring 2.00 mm x 2.00 mm (K5538)
Battery storage time (shelf life): Up to three years
Replacement: Every two years, or more often depending on dive activity
Life expectancy at 20°C/68°F:
0 dives/year –> 3 years
100 dives/year –> 2 years
400 dives/year –> 1 year
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 condi-
tions). 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 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.
10.2. RGBM
The SuuntoReduced Gradient Bubble Model(RGBM) is amodern algorithm for predicting
both dissolved and free gas in the tissues and blood of divers. It was developed in co-op-
eration between Suunto and Bruce R. Wienke BSc, MSc, PhD. It is based on both labor-
atory 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 circum-
stances 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
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