2021-07-21
Rev A
Page 15
Shearwater Petrel 1 & 2/Perdix/Perdix AI/NERD 2
Firmware v71 Release Notes
VERSION 71
2019-09-10
NOTE
A note on models:
The NERD 2, Petrel, Petrel 2, Perdix, and Perdix AI share a com-
mon firmware base. Due to hardware differences, not all features are available on all
models. The following changes apply to all models unless otherwise noted.
!
CHANGE
Changed how open circuit (OC) MOD PPO2 and Deco PPO2 limit settings are
applied. These limits determine the MOD of a gas, the PPO2 warning levels, and the
deco profile gas switch depths.
Rules for which PPO2 limit is used:
1. The enabled gas with the lowest O2 always uses the MOD PPO2 limit.
2. Gases above 40% O2 only use the Deco PPO2 limit (i.e. they are assumed to be
deco gases), except if 1) applies.
3. Gases 40% and below use the MOD PPO2 until deco stops are needed, at which
time they use the Deco PPO2 limit, except if 1) applies.
4. For “High PPO2” warnings, a 0.04 ATA buffer is used. For example, if the Deco
PPO2 is applicable and is set to 1.61 then:
• Above 1.57 = PPO2 displayed in yellow (but no warning).
• 1.65 or higher = PPO2 displayed in red and High PPO2 warning.
• This buffer does not apply to MOD depth calculations.
• This buffer does not apply to closed circuit (CC) PPO2 warnings.
(OC modes)
FIX
(AI models)
Fixed issue with incorrect display of SAC values in dive log.
IMPROVE
Improved font smoothing at edges of grayed-out text.
(all models)
