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ALTITUDE SENSING AND ADJUSTMENT
Prior to the first dive of a series of repetitive dives, Altitude (i.e., Ambient Pressure) is mea-
sured upon activation of Dive Surface Mode and every 15 minutes until a dive is made or
operation reverts to Watch mode after 2 hours.
> While it is operating in Watch mode after a dive, measurements are taken every 15
minutes during the 24 hour period after surfacing.
> Measurements are only taken when the unit is dry.
> Two readings are taken, the second reading 5 seconds after the first. The readings
must be within 1 foot (30 cm) of each other to record that ambient pressure as the
current Altitude.
The Mathematical Model in the ZEN accounts for the reduced No Deco Dive Times avail-
able based on National Oceanic and Atmospheric Administration (NOAA) guidelines.
When diving in high altitude waters from 3,001 to 14,000 feet (916 to 4,270 meters),
the ZEN automatically adjusts to these conditions providing corrected Depth, reduced No
Deco Dive Times, and reduced Oxygen Accumulation Times at Altitude intervals of 1,000
feet (305 meters).
No adjustments are made during any time that the Wet Contacts are wet.
At an elevation of 3,001 feet (916 meters), Depth Calibration automatically changes from
feet of seawater to feet of fresh water. This is the first adjustment to the Algorithm.
