Operations Manual Perdix
Manual DocRev B
10
Auto-On
The Perdix will automatically turn-on when submerged underwater . This is based on pressure
increase and not on the presence of water .
Auto-On Details
The Perdix turns on automatically when the absolute pressure is greater than 1100 millibar
(mbar) . For reference, normal sea level pressure is 1013 mbar and 1 mbar of pressure
corresponds to approximately 1 cm (0 .4") of water .
So the Perdix will automatically turn-on when about 0 .9 m (3 ft) underwater when at sea level .
If at higher altitude, then the Perdix auto-on will occur at a deeper depth . For example, when
at 2000 m (6500 ft) altitude the atmospheric pressure is only about 800 mbar . Therefore,
at this altitude the Perdix must be submerged underwater by 300 mbar to reach an absolute
pressure of 1100 mbar . This means the auto-on occurs at about 3 m (10 ft) underwater when
at an altitude of 2000 m .
TURNING ON
To turn the Perdix on, press both the MENU (left) and the SELECT (right) buttons at the same time .
This feature is supplied as a backup for when you forget to turn on your Perdix.
Shearwater recommends turning on manually before each dive to confirm proper
operation and to double check battery status and setup.
DO NOT RELY ON THE AUTO-ON FEATURE
