20
As you ascend from depth following a dive that has approached the
no decompression limit, the Nitrogen Bar Graph will recede as
control shifts to slower compartments. This is a feature of the de-
compression model that is the basis for multilevel diving, one of
the most important advantages that Aeris dive computers offer.
The no decompression algorithm is based upon Haldanes theory
using maximum allowable nitrogen levels developed by Merrill
Spencer. Repetitive diving control is based upon experiments de-
signed and conducted by Dr. Ray Rogers and Dr. Michael Powell
in 1987. Diving Science and Technology
®
(DSAT), a corporate af-
filiate of PADI
®
, commissioned these experiments.
Oxygen Accumulation Time Remaining
Oxygen accumulation (exposure) during a dive, or 24 hour period,
appears graphically as the Oxygen Accumulation (O2) Bar Graph
(Fig. 14a). As time remaining before reaching the oxygen expo-
sure limit decreases, segments are added to the O2 Bar Graph.
When the amount of time remaining before reaching the oxygen
limit becomes less than the No Decompression Dive Time Remain-
ing, calculations for that depth will be controlled by oxygen. Oxy-
gen Time Remaining will then appear as the main numeric time
display (Fig. 14b) as signified by the O2 Time icon appearing on
the display. As oxygen accumulation continues to increase, the O2
Bar Graph will enter the yellow Caution Zone.
Fig. 14 - O2 Accumulation
Dive Time Remaining
a
b
