Cochran Nemesis IIa NITROX, User Manual

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For example, if you were diving to 86 feet with NOAA II your PPO
2
level would be:
3.6 ( or 86
¸ ¸ ¸ ¸ ¸
33 + 1) X .36 = 1.296
which would be rounded up to PPO
2
= 1.3. PPO
2
levels from 0.5 to 1.6 are calculated.
Exceeding a PPO2 of 1.6 will greatly increase the probability of the immediate onset of
CNS Oxygen Toxicity. While various training organizations have established maxi-
mum PPO
2
limits, the maximum exposure times and their associated PO
2
levels used
in this dive computer's calculations are shown on the following table:
PPO
2
LEVEL Max Bottom Time (minutes)
.5 1304
.6 719
.7 496
.8 379
.9 306
1.0 257
1.1 221
1.2 194
1.3 172
1.4 149
1.5 110
1.6 44
Your dive computer calculates CNS or OTU toxicity percentages and it issues a unique,
five double-beep audible alarm once per minute should you reach 75 percent of the
associated maximum limit. In addition to this audible warning, the WARNING legend
will appear and flash AND the TEMPerature digits will be replaced with the current
calculated CNS Oxygen Toxicity percentage. This warning will continue until the calcu-
lated toxicity percentage is less than 75 percent. For example, the maximum bottom
time exposure for a PPO
2
level of 1.6 is 44 minutes. Once you reached 33 minutes of
bottom time with a PPO
2
of 1.6, this alarm would be issued since 33 minutes is 75%
of 44 minutes. At a PPO
2
of 1.5, this alarm would be issued at 82.5 minutes, etc.
NOTE: While all other audible alarms of the dive computer consist of five long
beeps, the toxicity audible alarm consists of short double-beeps that sound for five
seconds.
WARNING: It is possible in certain diving circumstances to reach an Oxygen Toxic-
ity limit well before reaching a no-decompression limit. For this reason, NITROX
diving should only be conducted by a diver who has successfully completed a
sanctioned NITROX diving course from a recognized certifying agency.