Specifications
98
OXYGEN EXPOSURE LIMITS (OTLS)
Predicted exposure limits and oxygen calculations of the ATMOS 
ai
are based on maximum exposure durations published by the National
Oceanic and Atmospheric Administration in the October 1991
NOAA Diving Manual (Fig. 94).
Both central nervous system (CNS) oxygen toxicity and pulmonary
oxygen toxicity were taken into consideration when the limits were
published by NOAA.
Although CNS oxygen toxicity is considered the primary constraint
for higher levels of PO2, there are circumstances in which pulmonary
oxygen toxicity can limit exposures.
CNS oxygen toxicity is not considered likely at PO2 levels below
1.30 ATA.  It is however related to the diver's work level.  Perform-
ing strenuous tasks could cause the symptoms of oxygen poisoning to
occur at PO2 levels lower than they normally would appear during
casual recreational diving.
WARNING:  The nitrox features of the ATMOS 
ai
 are
intended for use only by recreational divers trained
for nitrox diving by an instructor certified by a rec-
ognized training agency to teach diving with nitrox.
Maximum
Exposure Time
PO2
 (ATA)
 0.60
 0.70
 0.80
 0.90
 1.00
 1.10
 1.20
 1.30
 1.40
 1.50
 1.60
Per Dive
 (Min)
 720
 570
 450
 360
 300
 240
 210
 180
 150
 120
 45
Per 24hr
 (Min)
 720
 570
 450
 360
 300
 270
 240
 210
 180
 180
 150
Fig. 94 - OTLS










