O2 sensor values on CCR dives

[Davide DB]

On 4 December 2017 at 15:47, Jef Driesen <jef at libdivecomputer.org> wrote:

>
> Davide's data is the exception to the rule. It's the only dataset with CCR
> dives present, and an ADC offset of -1. I'm not sure what's going on there.
> The -1 could be a valid value here, but it would be really coincidence if
> all three sensors have the same ADC offset. All other datasets with CCR
> dives have different values for each sensor.
>
> I suspect the millivolt values already take into account the ADC value.
> Because if that's not the case, then I would expect to see large deltas
> between the stored average ppO2 and the manually calculated ppO2 after
> doing the millivolt conversion. The larger the ADC offset (absolute value),
> the larger the delta. But the cases where I see a delta larger than 0.02
> seems to be cases where one sensor is an outlier and was most likely voted
> out. But again Davide's dataset seems to be the exception here.
>
> Jef


I don't like to be an exception :)

How I can help?
Jef, do you remember I gave you two JJ CCR dataset coming from my buddies?
I don't know if they could be of some help.
I can ask to a friend of mine to download its data via dctool: we bought
our two SF2 units together.

Regarding the question if sensor #2 was voted out. I don't think so. When
one or more sensors are voted out their pO2 value is clearly displayed in
yellow. I never saw something strange going on in water. I guess even the
SD software should report a similar event which is not.
>From the Petrel manual I see that a sensor is voted out for a percentage
difference >= 20%. In the last part of my deco I see a max difference of
10% I think.


-- 
Davide
https://vimeo.com/bocio/videos
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