Oxygen Sensor Fundamentals

[Brad_Horn]

If anyone wants to read a bit more indepth into rebreather oxygen cell design, testing and failure modes, this resource is about the most detailed one available https://www.deeplife.co.uk/or_files/DV_O2_cell_study_E4_160415.pdf

Whilst SSS are alluded to in that report, their testing is covered separately (though this report is not public, yet!).

 

[tbone1004]

@RainPilot meant to adapt to other rebreathers... I didn't see the package for all of that when I looked. Had the CPOD/Cable/SSS for $2500ish and $2k for the M28 on DGX. That all said, it's still a massive investment to have to tack on for a single cell and the CPOD is impractical to add onto many rebreather designs so we will just have to wait

 

[RainPilot]

@RainPilot meant to adapt to other rebreathers... I didn't see the package for all of that when I looked. Had the CPOD/Cable/SSS for $2500ish and $2k for the M28 on DGX. That all said, it's still a massive investment to have to tack on for a single cell and the CPOD is impractical to add onto many rebreather designs so we will just have to wait

That 2500 includes the M28. Adding it as an independent cell reader is just a question of fitting it into the loop which Martin does all the time.

 

[bletso]

If anyone wants to read a bit more indepth into rebreather oxygen cell design, testing and failure modes, this resource is about the most detailed one available https://www.deeplife.co.uk/or_files/DV_O2_cell_study_E4_160415.pdf

Whilst SSS are alluded to in that report, their testing is covered separately (though this report is not public, yet!).

good report. Thanks

 

[tbone1004]

That 2500 includes the M28. Adding it as an independent cell reader is just a question of fitting it into the loop which Martin does all the time.

I told Poseidon when I talked to them that when they let it out to read 3 cells, or at least 2 cells, then I'll buy one on the spot. Until then, 0% chance.

 

[RainPilot]

I told Poseidon when I talked to them that when they let it out to read 3 cells, or at least 2 cells, then I'll buy one on the spot. Until then, 0% chance.

Perfectly reasonable requirement on your side, just need others seeing this to be aware that the 3rd cell option under 3k exists.

 

[wedivebc]

This is a presentation by Joe Citelli of IANTD on the fundamentals of O2 sensors. This is information that the majority of CCR instructors and vast majority of CCR divers do not understand. Presentation was birthed by @Bobby who has had passionate discussions about this with many of us and Joe decided to run with it. It's a long presentation, but I urge everyone who is actively diving CCR's or interested in diving CCR's to truly listen to this and absorb it. We all hope for a day when we have reliable and robust solid-state sensors where we no longer have to worry about these limitations of galvanic cells, but that day is not here yet and we all need to truly understand how our current sensor technology works.

Very interesting presentation. Once again though I have to take exception to your comment that the majority of instructors don't know something. I doubt you know even a small fraction of the CCR instructors in the world and an even smaller fraction of the CCR divers in the world and I would say that a majority of the CCR instructors and divers that I have trained have a pretty well rounded understanding of O2 cells as it applies to CCR diving.

 

[Jack Hammer]

I have no idea what the majority knows. I can say from personal experience that a lot of the ccr divers and instructors I've spoken with in a lotta places dont understand how a cell works and even less understood the simple relationship between mv and linearity.

 

[tbone1004]

Very interesting presentation. Once again though I have to take exception to your comment that the majority of instructors don't know something. I doubt you know even a small fraction of the CCR instructors in the world and an even smaller fraction of the CCR divers in the world and I would say that a majority of the CCR instructors and divers that I have trained have a pretty well rounded understanding of O2 cells as it applies to CCR diving.

you'd be surprised... Cell linearity is not taught by any agency that I'm aware of. There are many prominent instructors who deny it even exists. Cave country in Florida has a lot of CCR divers and instructors, the VAST majority down there have no idea...

 

[wedivebc]

you'd be surprised... Cell linearity is not taught by any agency that I'm aware of. There are many prominent instructors who deny it even exists. Cave country in Florida has a lot of CCR divers and instructors, the VAST majority down there have no idea...

That is likely very true. I was trained as a diver and instructor by Leon Scammahorn and I promise you he is very thorough about cell principals and I can assure you I cover it in detail in my classes as well. I would accept your claim regarding instructors and divers you know but since we run in different circles my experience is much different than yours.