The Care & Feeding of Your O2 Cell

[rjack321]

I have 2 teledyne sensors. I put the little aluminum caps from oxycheq on them, but I don't think they do much. Its mostly to keep water/dirt/gunk off of them. My garage is fairly cool for the majority of the year.

I have had sensors last anywhere from a month (complained to TDL and got another) to >2 years (still going). I have 2 analyzers and only replace them when they die.

 

[DwainT]

FWIW, I have been told by an extremely experienced ANDI instructor that one can speed up this "wake up" process by exposing a sensor to 100% O2 for a few hours.

This is not something that we at OxyCheq recommend... We tell everyone to take the sensor out of the bag at least 24 hours before use or calibration. Can you imagine diving on the wrong mix due to a cell not calibrating properly just after you pushed 100% O2 across it... Better yet, calibrating your rebreather wrong.

It's not worth your life... Open the bag 24 hours before use or remove the cap if you have it covered and let the sensor wake up.

BTW: I place a cap over mine...

Best Regards,
Dwain

 

[PacketSniffer]

This is not something that we at OxyCheq recommend... We tell everyone to take the sensor out of the bag at least 24 hours before use or calibration. Can you imagine diving on the wrong mix due to a cell not calibrating properly just after you pushed 100% O2 across it... Better yet, calibrating your rebreather wrong.

It's not worth your life... Open the bag 24 hours before use or remove the cap if you have it covered and let the sensor wake up.

BTW: I place a cap over mine...

Best Regards,
Dwain

Do you dive a rebreather? It really isn't possible to get a bad cal during calibration from one sensor on a multi sensor RB and you not see it and then dive it.

Personally, I would verify the sensor regardless if I recently opened it or not if using it in the analyzer.

Have you done any studies to say that the "O2 wakeup" does not work? I honestly have not been in the situation to consider the decision. I believe I already stated what is recommended. However, all information is useful. As I stated earlier, it came from a reputable ANDI instructor with thousands of dives and a lot of project experience.

 

[Mad_Max]

For what it's worth...
The wakeup period that PacketSniffer is referring to does actually exist. This actually refers to the fact the O2 cell has been exposed to N2 for an extended period of time and the N2 has completely diffused through the membrane and has flooded the inside of the cell. It takes time to flush the cell with O2 to completely remove all of the N2 which has defused through the membrane into the "business" side of the cell. With all the experience we've had with all different brands of O2 cells and analyzers, we've never tried this idea of flushing with %100 O2.
My only concern about this idea would be that you are now placing elevated %100 O2 inside the cell, rather than ambient O2 concentrations of %20.95. It may be that this has little to know effect. I have no idea. It would stand to reason that this practise would probably reduce the lifetime of the cell marginally.
We routinely calibrate our O2 cells using N2 as a 0 point. We always flush the cell with room air for 15 to 20 minutes following N2. That seems to work for us.
In our experience, the number 1 reason for premature cell death, is over pressurization.

Best,
Max