93
ALTITUDE SAMPLING/COMPENSATION
Atmospheric pressure decreases as Altitude increases above sea level. Weather systems and am-
bient temperature also affect barometric pressures. Consequently, depth reading instruments that
do not compensate for the decrease in ambient pressure indicate depth readings shallower than the
depth they are actually at.
The ATMOS ai automatically compensates for decreased ambient pressures for Altitudes between
2,000 (610 meters) and 14,000 feet (4,270 meters). Its program contains a high altitude algorithm
that reduces no decompression and oxygen exposure limits to add a larger zone of caution.
The ATMOS ai senses ambient pressure when it is activated, every 15 minutes while it is acti-
vated, or every 30 minutes when it is not activated. At an Altitude of 2,000 feet (610 meters), it
will automatically recalibrate itself to measure depth in feet of fresh water rather than feet of sea
water. It will then readjust the no decompression and oxygen limits at additional intervals of
1,000 feet (305 meters). Therefore, when returning to lower Altitudes, diving should not be con-
ducted until the unit automatically clears of any residual nitrogen and oxygen loading and resets
to operate at the new lower Altitude.
WARNING: The ATMOS ai will not sense ambient pressures or provide Alti-
tude compensation when it is wet. DO NOT dive at any different Altitude until
the unit shuts off and is reactivated at the new Altitude. If the unit is acti-
vated at elevations higher than 14,000 feet (4,270 meters), it will perform a di-
agnostic check followed by immediate shutdown.
