Petrel reading shallow

[crunchiespg]

I was doing a rescue class this weekend with multiple short, shallow dives. The computer was working fine at first but as the day went on it seems to start reading shallow. Some of the dives were only a minute or so, some were about 3 minutes, basically sink down to about 5-6 metres and then straight back to the surface simulating a rescue.
Quite a few times I was still 2-3m below the surface and the petrel would say I was at 0m. And the max depth would read 3m when it was at least 5.
This was altitude diving, and the computer was turned on before going down.

Do multiple short dives confuse the petrel? Or is there something else going on?

 

[OBXDIVEGUY]

the depth sensor is on the underside. Sometimes if it is too tight against a wetsuit, the sensor is covered up and gives false readings.

 

[tcoen]

I was doing a rescue class this weekend with multiple short, shallow dives. The computer was working fine at first but as the day went on it seems to start reading shallow. Some of the dives were only a minute or so, some were about 3 minutes, basically sink down to about 5-6 metres and then straight back to the surface simulating a rescue.
Quite a few times I was still 2-3m below the surface and the petrel would say I was at 0m. And the max depth would read 3m when it was at least 5.
This was altitude diving, and the computer was turned on before going down.

Do multiple short dives confuse the petrel? Or is there something else going on?

Hi Crunchiespg,

This problem does sound like an incorrect surface pressure reading. Contact us at support at shearwater.com so we can get the dive logs to confirm this.

Of note, we are releasing a new firmware update (v29) that changes how surface pressure is determined. It improves the accuracy of the surface pressure regardless of how the Petrel is turned on (by user, wet contacts, or depth activation), by keeping a history of the last ten minutes of pressure readings, even when off. More details will be in the release notes.

This is just being posted now, so hopefully will be available for download later in the day.

Best regards,
Tyler Coen
Shearwater Research

---------- Post added July 14th, 2015 at 10:32 AM ----------

the depth sensor is on the underside. Sometimes if it is too tight against a wetsuit, the sensor is covered up and gives false readings.

Hi OBXDIVEGUY,

Some of the very early production units only had one port to the depth sensor on the bottom of the unit. This was addressed within the first few months by adding another port to the front of the unit.

If your unit does not have the front hole, please contact us as we can rework your unit to add this extra port.

Best regards,
Tyler Coen
Shearwater Research

 

[crunchiespg]

Hi Crunchiespg,

This problem does sound like an incorrect surface pressure reading. Contact us at support at shearwater.com so we can get the dive logs to confirm this.

Of note, we are releasing a new firmware update (v29) that changes how surface pressure is determined. It improves the accuracy of the surface pressure regardless of how the Petrel is turned on (by user, wet contacts, or depth activation), by keeping a history of the last ten minutes of pressure readings, even when off. More details will be in the release notes.

This is just being posted now, so hopefully will be available for download later in the day.

Best regards,
Tyler Coen
Shearwater Research

Yeh I knew about the potential for this issue so I made sure the computer stayed on pretty much all day long.
ill contact you and send you the logs I have. I did delete a few as I wanted the logs to match the actual number of dives we logged for that class.

---------- Post added July 14th, 2015 at 06:31 PM ----------

unfortunately i just looked and the logs i deleted are the problem logs. i had to delete them to keep my numbers in line for later proper dives.

v29 isn't showing as available yet, any idea when?

 

[BFRedrocks]

v29 isn't showing as available yet, any idea when?

Looks like it's up on the website now. I haven't downloaded it to my computer yet, but it seems to be available.

 

[JohnnyC]

Tyler,

You guys planning on adding the same non-compass related stuff to the Predator? What can I say, I still like my Predator