Question Flush O2 sensor with CO2 when not in use ?

[JohnN]

Would flushing an airtight container with CO2 and storing the galvanic O2 sensor when not in use increase its useful lifetime?

I have a tank of CO2 (I keg apple cider) available, I don't see how it could hurt, but I practice omniscience only when I'm underwater

 

[tbone1004]

it won't hurt, but it will take a bit to "wake up" after it sees fresh air again. I would not trust it until it's been out in the air for at least 4-6 hours, especially for a rebreather.

 

[davehicks]

Probably not worth the effort. The sensors have a shelf life even in their original sealed packaging. Expect them to have a useful life of 12 months +/- 6 months. Always keep a few spares handy.

 

[JohnN]

Thanks @davehicks and @tbone1004

 

[broncobowsher]

Another "no".

I'm thinking of CO2 + H20 = carbonic acid. Not the environment I want to store electronic stuff in.
I doubt there is any research into long term effects of storing in a high CO2 environment.

From my years of researching this stuff, don't try anything heroic in trying to make them last longer. Store them in clean air in temperature controlled environment and be done with it.

 

[JohnN]

Another "no".

I'm thinking of CO2 + H20 = carbonic acid. Not the environment I want to store electronic stuff in.
I doubt there is any research into long term effects of storing in a high CO2 environment.

From my years of researching this stuff, don't try anything heroic in trying to make them last longer. Store them in clean air in temperature controlled environment and be done with it.

Im not quite sure where the water is coming from, my use is strictly for EAN mixes

Since we’re talking basic chemistry, IIRC, reducing the temperature by 10oC halves the rate of reaction for 1st order diffusion reactions. That said, a dry -20oC (from ambient ) differential should significantly increase the lifespan of the sensor

 

[Snusmumrik]

Galvanic cell sensors like common O2 cells use potassium hydroxide (KOH) as electrolyte.
KOH reacts with CO2 and forms potassium (hydro)carbonate, thus depleting electrolyte in sensor and reducing it's life.

Nitrogen flush and cold storage (domestic fridge) can be used to slightly expand cells life.
Freezing cells not recommended.

 

[justinthedeeps]

Probably not worth the effort. The sensors have a shelf life even in their original sealed packaging. Expect them to have a useful life of 12 months +/- 6 months. Always keep a few spares handy.

We know and follow the rules for good reasons, but I'm curious--is there any actual public data/tests for this?
Do cells 'go bad' just as quickly in the packaging, or do they not?

Another example, teams have experimentally tested (and verified) active diving durations on scrubber life--but I don't remember seeing any tests of how much (or whether) a sealed tub of unused sorb actually 'goes bad' under recommended storage conditions, or how long that takes. ('5 years' sounds regulatory, not scientific.)

 

[Snusmumrik]

We know and follow the rules for good reasons, but I'm curious--is there any actual public data/tests for this?
Do cells 'go bad' just as quickly in the packaging, or do they not?

Never seen any "actual public data/tests", but my practice for near 15 years show that most cells
die instantly after 1,5-2 years of sealed package shelf life, so storing cells for more
than 6 month for me is not a good practice.

PS One time i got a cell from divegearexpress, that was installed just after arrival, starts dying after 4 years and completely died after 4,5 years of active life in rebreater.