Shearwater Petrel EXT, Operation Manual, Page: 51 / 65

Shearwater Petrel
Revision 1.1.0 51 Shearwater Research Inc.
O2 Setup
This menu page is only available in Closed-Circuit (CC) or Semi-
Closed (SC) mode when PPO2 mode is set to external (see Dive
Setup page)�
Cal. FO2
This setting allows you to set the fraction of oxygen (FO2) of the
calibration gas�
In CC mode, the calibration gas FO2 can be set from 0�70 to 1�00�
The default value of 0�98 is for pure oxygen, but assumes about
2% water vapor due to the diver’s breathing on the loop during the
flushing process.
In SC mode, the calibration gas FO2 can be set from 0�20 to 1�00�
This is because semi-closed divers do not always have oxygen
available�
Note: When in SC mode the user cannot utilize internal PPO2
monitoring�
Sensor Disp
Sets the sensor display mode on the center row of the main screen�
In CC mode, the available settings are:
• Large: the PPO2 text is the normal large font�
• Giant: the PPO2 text is larger�
In SC mode, the available settings are:
• PPO2: the PPO2 is shown�
• FiO2: the Fraction of inspired O2 (FiO2) is shown�
• Both: PPO2 shown is large font, FiO2 below in small font�
Auto SP (Setpoint) Switch
This menu page is only available in CC mode when PPO2 mode is
set to internal (see Dive Setup page)�
Auto Setpoint Switch configuration sets up the setpoint switching. It
can be set up to auto switch up only, down only, both, or neither�
First, you set the whether the “Up” switch occurs automatically
or manually� If “Up” is set to “Auto”, then you can set the depth at
which the auto switch occurs�
‣ O2 Setup
Cal. FO2
Sensor Disp
Next Edit
O.98
Giant
‣ Auto SP Switch
Up: O.7>1.3
Up Depth
Down: 1.3>O.7
Down Depth
Next Edit
Auto
O7Oft
Auto
O4Oft
O2 Setup
Cal. FO2
‣ Sensor Disp
Change Save
O.98
FiO2
DEPTH TIME STOP TIME
96% 97% 97%
O2/HE NDL TTS
CC 21/OO O O
O
In SC Mode, the center
row can show FiO2
instead of PPO2