Oxygen exposure – SUUNTO VYTEC User Manual

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Also on repetitive dives adjustment may be applied to the maximum

allowable nitrogen overpressure in each theoretical tissue group.
Depending on circumstances Suunto RGBM will adapt the decompres-

sion 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).

Diver Attention Symbol Advice to Extend Surface Interval. If attenuat-

ed RGBM (RGB50) has been set, the Diver Attention Symbol will also

be shown to indicate it.
Some patterns of diving cumulatively add a higher risk of DCI, e.g. dives

with short surface intervals, repetitive dives deeper than earlier ones,

multiple ascents, substantial multiday diving. When this is detected in

addition to adapting the decompression algorithm the Suunto RGBM

model will in some circumstances also advise, with the Diver Attention

Symbol (review chapter 3.6) that the diver extend the surface interval.

6.3. OXYGEN EXPOSURE

The oxygen exposure calculations are based on currently accepted

exposure time limit tables and principles. In addition to this the dive

computer uses several methods to conservatively estimate the oxygen

exposure. These include for example:

the displayed oxygen exposure calculations are upped to the

next higher percentage value

for recreational scuba diving, the recommended upper limit of

1.4 bar PO

is used as a default

the CNS% limits up to 1.6 bar are based on 1991 NOAA Diving

Manual limits

the OTU monitoring is based on the long-term daily tolerance

level and the recovery rate is reduced

Oxygen related information displayed by the dive computer is also de-

signed to ensure all warnings and displays in the appropriate phases of

a dive. E.g. the following information will be shown before and during a

dive, when the computer is set in Nitrox mode:

the selected O

the color-coded OLF% bar graph for either CNS% or OTU%

audible alarms are given and the OLF bar graph starts to blink

when the 80% and 100% limits are exceeded