Page 63
Doc. 13301-Tec-RevB (2022-05-25)
Technical Modes
Operating Instructions
11.1. Mode Setup
The first sub-menu of System Setup is Mode Setup�
The appearance of this page changes depending on
the selected mode�
Mode
There are 6 available dive
modes:
• Air
• Nitrox
• 3 GasNx (default)
• OC Tec
• CC/BO
• Gauge
(E�g� bottom timer mode)
This manual only covers OC Tec, CC/BO, and Gauge
mode� For the other modes, please see the Perdix 2
recreational diving manual�
When changing to or from Gauge Mode, the
decompression tissues are cleared� This is because the
Perdix 2 does not know what gas you are breathing
in this mode, and therefore cannot track inert gas
loading� Plan repetitive dives accordingly�
For more information on which mode to choose, see
Dive Mode Differentiation on page 10�
Mode CC/BO
Salinity EN13319
PPO2 Mode
Int.
Low SP 0.7
High SP 1.3
Next
Edit
Mode Setup
Salinity
Water type (salinity) affects how the measured
pressure is converted to depth�
Settings:
• Fresh
• EN13319 (default)
• Salt
Density of freshwater and saltwater differ by about
3%� Saltwater, being denser, will display a shallower
depth for the same measured pressure versus the
Fresh setting�
The EN13319 value is between Fresh and Salt� It is
from the European CE standard for dive computers,
and is the Perdix 2’s default value�
Note that this setting only affects the depth
displayed on the computer and has no impact on
decompression calculations which rely on absolute
pressure�
PPO2 Mode
PPO2 mode only appears in CC/BO mode�
On the Perdix 2 this value is always “Int�” (Internal
fixed PPO2)� On other models of Shearwater
computer, this value can be changed to “ext�”
when external O2 cells are used for decompression
calculations�
Low and High Setpoints
The Low and High PPO2 Setpoints are only available
when CC is enabled�
Each setpoint can be set from 0�4 to 1�5�
The setpoints can also be edited during a dive, in the
Dive Setup menu�
CC ONLY
CC ONLY