O2 sensor values on CCR dives

[Anton Lundin]

On 17 November, 2017 - Davide DB wrote:

> On 17 November 2017 at 19:10, Anton Lundin <glance at acc.umu.se> wrote:
> > On 17 November, 2017 - Davide DB wrote:
> >
> >> Looking to one of my CCR dives (Petrel 2 controller) I realized that
> >> Po2 values reported by Subsurface at the 6 meter stop are way higher
> >> than those recorded and displayed by Shearwater Desktop.
> >> I'm 100 sure that Shearwater Desktop shows correct values because I
> >> perfectly remember O2 values I was seeing at 6 meter: I was never
> >> never never over 1.6 for all the time.
> >> According to Subsurface profile I was all the time at 6m over 1.6 with
> >> spikes at 1.75.
> >> Am I missing something?
> >>
> >> I chose a point in time (122' 50")and I attach three screenshots:
> >>
> >> Shearwater (which display only the AVG pO2)
> >> Subsurface with single pO2 sensor display
> >> Subsurface with AVG pO2 sensor display
> >
> > Could you dump the raw data from the device?
> >
> > It can be done using either dctool or using the predator protocol and
> > creating a device dump.
> >
> >
> > You could probably just send a log file of the download, I think I still
> > got the tool to replay a log file as a download.
> >
> >
> > Then I can take a look at the raw data to try to figure out what's going
> > on.
> >
> >
> > //Anton
> 
> 
> After depleting one battery here are.
> 
> Dctool is a lucky process. 99% of the times I get errors like this:
> 
> [73.192176] ERROR: Failed to receive the response packet. [in
> ../../source/src/shearwater_common.c:319 (shearwater_common_transfer)]
> [73.192715] ERROR: Failed to download the dive. [in
> ../../source/src/shearwater_petrel.c:266
> (shearwater_petrel_device_foreach)]
> [73.193107] ERROR: Error downloading the dives. [in
> ../../source/examples/dctool_download.c:218 (download)]
> [73.193712] INFO: Write: size=9, data=FF0105002E902000C0
> 
> Raw file for the dive attached

I've now looked at the data in the file, and the ppo2 values for the
individual sensors are definitely bit high compared to the stored
average value.

I'll take a look at the data to try to figure out what might be going
on.


//Anton


-- 
Anton Lundin	+46702-161604