O2 sensor values on CCR dives

[Anton Lundin]

On 11 December, 2017 - Davide DB wrote:

> On 11 December 2017 at 15:59, Anton Lundin <glance at acc.umu.se> wrote:
> > On 11 December, 2017 - Davide DB wrote:
> >
> >> On 11 December 2017 at 10:16, Anton Lundin <glance at acc.umu.se> wrote:
> >> >> I calibrate my two Petrels ALWAYS when I assemble my unit as part of
> >> >> my checklist and ALWAYS the same day I dive and. No calibration No
> >> >> party.
> >> >> I made other dives and all of them show the same error. Shearwater
> >> >> desktop tell me that everything is ok (like my Petrel underwater)
> >> >> while Subsurface reports pO2 over 1.6.
> >> >> Thank you for the detailed explanation.
> >> >> Where do we go from here?
> >> >
> >> > Is this a divecan unit or something?
> >> >
> >> > I'm just guessing that it might affect how/where the cal factors are stored.
> >> >
> >> >
> >> > //Anton
> >>
> >> Yes, divecan unit.
> >
> > There we go. Thats probably why its the factory default cal factors that
> > are stored in the header, and not the real ones. It might be that the DC
> > doesn't even have them, and its only the sensor board which know them
> > for real.
> >
> >
> > My suggestion then is to not show individual sensor ppo2's, if the cal
> > factor is 2100, and just emit the average ppo2 then.
> >
> > At least that one is accurate.
> >
> >
> > The best would be if we had a interface which let us both expose the
> > average ppo2 and the raw mV values.
> >
> >
> > //Anton
> 
> Hi Anton,
> 
> The strange thing is that also the other dataset from my dive friends
> came from divecan units (JJ).
> IIRC those dataset haven't this problem.

When I read the thread again, from the snippets Jef posted all those
have cal factors of 2100, so I'm guessing those ppo2-values are
inaccurate to.


Jef: could you verify this against the average ppo2 in those mem dumps?


//Anton


-- 
Anton Lundin	+46702-161604