Oceanic ATOM Operating Manual - page 91

91

against a maximum allowable Nitrogen level.  Whichever one is

closest to this maximum level is the controlling compartment for

that Depth.  Its resulting value will be displayed numerically along

with the symbols NDC and TIME (Fig. 80a) and graphically as

the Nitrogen Bar Graph (Fig. 80b).

As you ascend from Depth following a dive that has approached

the No Decompression Limit, the Nitrogen Bar Graph segments

will recede as control shifts to slower compartments.  This is a

feature of the Decompression Model that is the basis for Multi-

level Diving, one of the most important advantages that Oceanic

dive computers offer.

The ATOM's algorithm is based upon Haldane’s theory using

maximum allowable nitrogen levels developed by Merrill Spen-

cer.  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

affiliate of PADI

®

, commissioned these experiments.

Oxygen Accumulation Time Remaining

Oxygen Accumulation (saturation or exposure) during a dive, or

24 hour period, appears graphically as the O2 Bar Graph when

the Alternate #2 (O2) screen is accessed (Fig. 81a).  As time

remaining before reaching the Oxygen Exposure Limit decreases,

segments are added to the O2 Bar Graph.

Fig. 81 - O2 Bar Graph

Fig. 80 - Nitrogen Bar Graph

b

a

a