Need help for decision Xccr vs liberty or BMoptima

[stuartv]

These O2 sensors have been in industry for a lot of years, no different than galvanic cells, diving is not a priority for this market.

So, they can survive a bath in caustic with no issues? Galvanic cells can usually handle that and continue to be used (on future dives). You're saying these SS sensors are no different, so they can also handle a caustic bath and generally be expected to continue to work after cleaning up post-dive?

As far as safety improvements, it is about failure modes. Failure on a galvanic cell usually results in inaccurate readings which have lead to fatalities and near-misses because people think they are breathing one gas and not what is actually in the loop. Solid state cells when implemented in a full digital system have signal validation and are either "working" or "dead", no risk of misinformation from the cells is a huge safety improvement. I'd much rather a cell be dead than have it give me bad information

And so we have 3, 4, or 5 cells. How many CCR divers have been injured or died in the last, I don't know, 5 years, who followed their training (including maintenance), because of misinformation from their O2 sensors?

Even anecdotally. How many have you heard of?

 

[SavageSeaCow]

I love how the solid state vs galvanic ends up being the focal point of all rebreather discussions these days I can’t wait for some to actually be in circulation so that we can have some real data/experience. Lots of experience on SB but I’m not sure any of it will help the OP. It’s almost impossible to know what you will like or hate about a unit until you spend a few hours on the loop. I will say that ease of getting parts and service is a big consideration. If you’re super undecided and you’ve actually tried them, go with the one that costs less.

In all seriousness the divesoft option is best if you’re really into cutting edge tech and a company that is doing cool and innovative things. If that’s not important to you it’s a hefty price difference for a tube with sorb. I would go with the optima if it has to be one the three. Shearwater electronics are reliable and have good service.

Of course the right answer is you should get a rEvo but…

 

[kissonerga.ccr]

How many CCR divers have been injured or died in the last, I don't know, 5 years, who followed their training (including maintenance), because of misinformation from their O2 sensors?

If they died, how do we know with any certainty though? If they followed their training. Or were duped by a faulty sensor or two. It’s not like we get to read an NTSB-level post-accident report in most cases

I’m not saying SS sensors are the magic bullet, I’m happy to continue to dive galvanics. But my next machine will have an SS box

 

[stuartv]

If they died, how do we know with any certainty though? If they followed their training. Or were duped by a faulty sensor or two. It’s not like we get to read an NTSB-level post-accident report in most cases

I’m not saying SS sensors are the magic bullet, I’m happy to continue to dive galvanics. But my next machine will have an SS box

I'd like to hear about near-misses, too. But, a download of the controller's log should show if the sensors would giving readings that could have contributed. E.g. 2 cells showed 1.2 and 1 cell showed 1.8.

Of course, I do understand how unlikely it is that we'd see such a log...