Specifications

87
500AI
OXYGEN EXPOSURE LIMITS
Predicted exposure limits and oxygen calculations of the 500AI are based on
maximum exposure durations published by the National Oceanic and Atmo-
spheric Administration in the October 1991 NOAA Diving Manual (Fig. 86).
Both central nervous system (CNS) oxygen toxicity and pulmonary oxygen tox-
icity 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. Performing strenuous tasks could
cause the symptoms of oxygen poisoning to occur at PO2 levels lower than
they normally would appear during casual recreational diving.
The nitrox features of the 500AI are intended for use only by recre-
ational divers trained for nitrox diving by an instructor certified by a
recognized training agency to teach diving with nitrox.
Fig. 86 - Oxygen
Exposure Limits
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