Oceanic GEO 2 Operating Manual - page 70
70
OTR (O2 DTR)
When set for Nitrox operation, O2 during a dive is displayed
on an ALT screen as a % of allowed saturation (Fig. 71a) identi-
fied by the O2SAT icons.
The limit for O2 exposure (100%) is set at 300 OTU (oxygen
tolerance units) per dive or 24 hour period. As time before
reaching the limit decreases, % O2 increases and OTR (O2
DTR) decreases.
When OTR becomes less than the NDC, calculations for the dive
will be controlled by O2 and OTR will be displayed as DTR on
the Main (Fig. 72a), identified by the O2 and min icons.
a
Fig.71-NODECOALT1
a
Fig.72-NODECOMAIN
PO2
(ATA)
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
1.60
Max Duration
Single Exposure
(min) (hr)
720 12.0
570 9.5
450 7.5
360 6.0
300 5.0
240 4.0
210 3.5
180 3.0
150 2.5
120 2.0
45 .75
Max Total Duration
24 Hour Day
(min) (hr)
720 12.0
570 9.5
450 7.5
360 6.0
300 5.0
270 4.5
240 4.0
210 3.5
180 3.0
180 3.0
150 2.0
OXYGEN EXPOSURE LIMITS
(from NOAA Diving Manual)