petrel 2 help?

[crunchiespg]

i used my petrel for the first time today. just a few short dives in a shallow lake, max depth was 7 metres for 30 minutes..
when surfacing, we didn't really do a safety stop as the entire dive was around 4metres apart from the one little dip to 7m.
on the surface my petrel came up "error low pp02" .. why was that?
I'm in recreational mode, using air.
thank you.

 

[rhwestfall]

eare you sure it's at all the defaults (or did you change some parameters)?

 

[crunchiespg]

eare you sure it's at all the defaults (or did you change some parameters)?

Nope. Other than basic settings like units and stuff.
I can't see an option to edit the low pp02. The high pp02 is still at the default 1.4.

 

[rhwestfall]

post it to Shearwater's page. They are awesome for analyzing the issue and responding....

 

[tcoen]

I posted this to another thread. Re-posted here for those that might only see this thread.

Hi crunchiespg,

The cause for the low PPO2 message is the altitude at which you are diving. The default low PPO2 warning limit is 0.19 ata [atmospheres absolute]. Since PPO2 is ambient pressure multiplied bythe FO2 (21% for air), the PPO2 near the surface can easily fall below 0.19 near the surface.

For example, at 4500ft elevation the ambient pressure is about 0.85 ata, resulting in a PPO2 breathing air of 0.1785 ata.

The low PPO2 warning level can be adjusted, but unfortunately not when in the OC Rec mode. But you can adjust it in the OC tec mode, then switch back to OC Rec mode and the value will stick. Steps:
- Switch to OC Tec mode.
- Go to "System Setup->Adv Config->Adv Config 2"
- Change the OC Low PPO2 setting to something lower like 0.17
- Swtich back to OC Rec mode.

I hope this helps answer your question.

Best regards,
Tyler Coen
Shearwater Research

 

[Father]

I've actually gotten this message too.... and I dive in the ocean.
I usually just hit buttons until it goes away. Don't know why it does it though.

 

[Dhboner]

Another home run by Shearwater support!