38
Figure 12: PO
2
Warning.
Be aware that, should the PO
2
Warning activate
at a depth of 20 ft/6m or less, you most likely
have not
exceeded a limiting PO
2
of 1.6 atmos-
pheres. What is more likely is that you forgot to
set the
IQ-600
’s FO
2
prior to the dive. As a
result, the computer has defaulted to an assumed
FO
2
of 99 percent oxygen. Such a high FO
2
will,
of course, set off the PO
2
Warning prematurely.
See page 42 for more information on why and
how the
IQ-600
’s FO
2
setting defaults, and its
implications.
Oxygen Limit Index (OLI) Warning—The IQ-600’s
Oxygen Limit Index (OLI) reflects the cumulative effect of
your exposure to elevated partial pressures of oxygen.
Where as the PO
2
Warning accounts only for the intensity
of such exposure, the OLI accounts for both its intensity
and length.
