02 Sensor Storage

grandizer52

Ok Divers...so you get done diving, you clean your RIG, How/what is the best way to store sensors? since abandoning the oxygauge cause...well to be fair, i didn't like it and went with a shearwater...how do my fellow divers store there 02 sensors...specially if yours are in a fixture mounted...
thanx

laytah
steve

decoweenie

Your options include:

1. Keep them in the rig. You will get about a year of use out of them.
2. Take them out, put in a box void of air. You will get about 12 months of use out of them.
3. Take them out, put in a box and fill with Argon. You will get about 365 days of use out of them.

(plagiarize from someone on NWRB, I think it was Kevin Juergensen )

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"...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..."

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Marc T

I let them in my Rebreather all the time ( because its difficult to take them out ) but after diving I rinse RB with air or diluent before closing the mouthpiece ( more specially if It let the sorb inside ) to avoid the sensors to be in a high ppo2 environment.

Bill

In the rig, in air. I keep the loop open, ambient, but do use some cutup ODs on tee pieces and hose ends to keep the critters out between dives (I'm sure you are familiar with the geckos, roaches, ants, centipedes, etc. around here). Importantly, cells (consumables) get ditched after a year or so (based on date of manufacture, not instillation into the lid) and cell checks are executed at 20ft every dive.

If you diss the cells they will try to take your life....

B

jaap

I think this is a mysterious subject.

A long time ago, like 10+ years ago or so I learnt that cells would live longer if stored under more inert conditions. Like by using an o-ring sealed cap on the cells. And maybe even store the cells in the refrigirator (like you can do to prolong the shelf life of batteries).

For my really old nitrox analysis O2-cells those tricks actually seem to work.

But for some reason it does not seem to do much to extend the life of cells used in a Rebreather.

My hypothesis is that maybe Rebreather-cells age in a different way. Maybe its a combination of: Faster accumulation of '02/hours' compared to a cell used for gas bledning analysis. Corrosion on the board. Pressure effects on the front/backside membranes. Maybe this is promoting say loss of electrolyte or O2 sneaking in by the backside bypassing a cap over the membrane?

There must be some positive effect from shielding the cells from O2 during storage. It think it makes sense from an chemistry standpoint and many manufacturers use it to extend the shelf life.

One interesting side track from this is how the different manufacturers ship their cells. When opening a cell that comes in a sealed metallic can I always check the mV output immediately. They almost always read very low close to 0 mV before they wake up properly.

But when I rip open the sealed plastic bag that say the Analytical Industries cells come in they often show a high mV right away with little to no display of any wake up rise in mV.

Maybe this is one of the reasons Analytical Industries generally states a shorter shelf life compared to other manufacturers?

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