How many sensors should I replace on rEvo after 8 months of not diving?

[James Ocean]

Hi all,

I installed 5 new rEvo/Vanadagraph cells into my rEvo III 12 months ago (had to replace all 5 as it was a used rig purchase) but haven't dove it for 8 months now, and haven't replaced any cells since.

Petrel & Dreams are on my rig.

I'd like to start using the DGX/Analytical cells. Do I need to replace all 5 cells to not mix them with the rEvo/Vandagraph cells?

Can I just place 2 or 3 cells and if so, in what sequence?

 

[rjack321]

Personally if the cells were stored in reasonably climate controlled conditions (not 35+C all summer). I would just dive them until the 12month mark and start replacing them then in whatever rotation schedule you have decided on. Perhaps run them through a pressure pot to ensure they are still linear and reaching 1.8-2+

Replacing some now? There is no real reason for that IMO.

I won't run a cell over 12 months but plenty of revo divers do based on various arm waving exercises that make no sense to me, so can't help you there.

 

[davehicks]

If they test well then don't replace them. It is not like they wear out faster when you don't use them.

 

[James Ocean]

Thanks for the replies. Just to clarify:

- Cells were all replaced 12 months ago
- Used it for 4 months and did about 12 dives
- Haven't used it for 8 months now. Stored indoors in dry normal room temperatures

 

[davehicks]

Cells can last 2years easily but as mentioned some swap preventatively more often. Its your choice. Remember that these cells are reacting as long as they are exposed to oxygen. So they are a year old whether you use them diving or not.

 

[Superlyte27]

What’s the “Do Not Use After” date day? And then follow that.

 

[Heat Miser]

Revo policy 3 would have you swap out/in 2 new cells.

However it doesn't suggest swapping in more than one new cell at a time, because there is a diversification benefit from having cells from different batches in the system. Assuming all 5 cells were good 8 months ago? And assuming you are regularly doing cell verifications at 6m to test. Swap in 1 new cell into position 2 center console on the shearwater solenoid. and swap in another new cell in a months time from a different batch. Going forward after 1 months time replace a cell at least every 6 months. Using policy 3:

• Understanding Oxygen Sensors
• Understanding Oxygen Sensors Part II – The Complete Picture

 

[rjack321]

Revo policy 3 would have you swap out/in 2 new cells.

However it doesn't suggest swapping in more than one new cell at a time, because there is a diversification benefit from having cells from different batches in the system. Assuming all 5 cells were good 8 months ago? And assuming you are regularly doing cell verifications at 6m to test. Swap in 1 new cell into position 2 center console on the shearwater solenoid. and swap in another new cell in a months time from a different batch. Going forward after 1 months time replace a cell at least every 6 months. Using policy 3:

• Understanding Oxygen Sensors
• Understanding Oxygen Sensors Part II – The Complete Picture

It's a shame these memos don't actually have any empirical data behind them

 

[broncobowsher]

It's a shame these memos don't actually have any empirical data behind them

Click the links and enjoy swimming through data.

I would probably replace 2 (one in controller and one in whatever display you are running). Start working on my rotation schedule.

I'm going to be in the same boat next spring. I took a knee out this past summer and while actual diving it wouldn't be an issue, the walking on shore, rocking dive boat, dive ladder stuff I can't do. Have some surgery lined up and know it will be a few months of recovery. When I get back in I'll probably need half of them.

 

[rjack321]

Click the links and enjoy swimming through data.

Paul made up those statistics, they are hypothetical failure rates. There is no database of cell failures anywhere