@stuartv voting logic has nothing to do with your brain on a shearwater. It is controlled solely by the computer with no override other than manual setpoint control Within the range you are allowed, nor does it allow you to have accurate decompression calculations because it is using the wrong ppO2. The revo gives you the ability to see a ppO2 reading from an independent system but you are still required to have an off board decompression plan because the onboard shearwater is now useless. In this regard the Liberty is vastly superior because you can disable the cells which allows the unit to function normally with regards to decompression and solenoid function.
Liberty allows you to disable the cells that your brain votes out as invalid, they go away, that is vastly superior than having to continuously override a system that is actively malfunctioning. If your brain is the final decision maker, then disabling a bad cell is superior. The revo has independent monitoring systems but it is not redundant because the Dreams can't do anything for the units function. That said, if your brain is the final decision maker, why do you need 5 cells on 3 independent systems to tell you what's going on? Your brain knows what is going on, you need to be able to tell the computer what to do. Shearwater does not allow you to do that which requires you to manually change the setpoint as low as it will let you and/or shutoff the feed to the solenoid so it doesn't tox you, AND requires you to have offboard decompression. With the Revo you have the Controller, HUD, Dream1, Dream 2, and a separate computer to track constant ppO2 for decompression to safely conduct a dive. With the Liberty you need one controller, one backup controller, and one HUD to have the same function.
I have mentioned many times having a NERD2 as a monitor. I don't know why you would insist on using an example of a rEvo with Dreams so that you can support your argument. You make your whole argument invalid when you base it on a different configuration than the one under discussion.
A rEvo with a Predator/Petrel controller and a NERD2 monitor does indeed allow me to have accurate deco calculations even in the scenario where 2 cells have become current-limited at the same time and voting logic causes 1 good cell to get voted out.
It is true (as far as I know) that IF 2 cells on the rEvo controller both go out at the same time - and in the same way - so that they are wrong, but the controller decides they are right and votes out the one good one, I would have no control beyond setting the controller to the low SP. So? I do not see how that means that the Liberty is "vastly superior". Mainly because the chances of that happening are so infinitesimal, and the consequences are so benign (when I have a completely independent monitoring system that still gives me real-time deco calcs), that I think it is a complete exaggeration to say that that makes the Liberty "vastly superior". The only real consequence, if that were to happen to a rEvo (with NERD) is that the user would have to run the unit manually for the rest of the dive - and even then, that is only to avoid continuing to dive at a SP of 0.7.
I change my SP to its low setting and fly my unit manually, with accurate real-time deco calcs - using my NERD.
rEvos are available from the factory as a manual unit, in this configuration so you can't even keep saying it's a "malfunctioning unit" or other such nonsense.
With 5 sensors, any 2 can pack off at any time. If they are both on the controller, then, IF they both pack off the same way - i.e. they both become current limited at the same time, to the same amount - then in that one scenario, I would have to change to low SP, fly manually, and follow my NERD for deco calcs. That is pretty dang low risk and low effort if it happens. And, as a matter of fact, I have had 2 pack off on my controller before (when I flooded my inhale lung due to my own stupidity) and I did just that. Finished the dive flying manually, using my NERD for deco calcs.
I also had the solenoid pack off while diving the Jodrey once. I had to fly it manually for the rest of the dive on that one, too. Flying it manually is no big deal. It's a lot easier, with the CMF, than flying a unit manually that is electronic only.
Saying that the Liberty is vastly superior because, in the same situation, you don't have to fly it manually (but you ARE letting it be controlled based on only 1 cell) does not compute, to me.
How much is "one load" and what is the water temp?
Call me crazy but I would do 6 hours on my 6.5lb Meg axial scrubber in warm water (Mexico, Bikini, Truk, etc).
I would not do 3 hour dives in the ocean though. Way too much can change topside in 3hrs. A thunderstorm could be especially hazardous for instance.
"One load" means one scrubber can full. Discussing apples to apples would mean a can that holds approximately the same amount as what the 2 rEvo baskets hold, combined.
I wouldn't call you crazy at all. But, I would observe that in warm water like that, I would also be pretty likely to use the same amount of sorb, except that when you are diving on the "last" part of the sorb in your 6.5# scrubber, I will have swapped out a basket for a fresh one. So, when we're all done, we'll have used the same amount of sorb. But, during those last (say) couple of hours, you'd be diving with whatever margin you have - presumably not much - and I'd be diving with a new basket of sorb in the bottom of my unit, giving me a much greater margin of safety. After the dive, I'd toss my top basket and move the bottom one to the top to use on my next dive. You'd toss your whole can full. So, we burned the same amount. But I had a better margin of safety on the last part of our diving.
As for 3 hour dives in the ocean, all I can say is that I haven't done one. My ocean dives of any length have been wreck dives. None shallow enough to do a long dive with no deco. As you know, once you start racking up deco, the dive gets kind of self-limited. 25 minutes on a 250 wreck gives an hour or so of deco and are limited to about that by available BO. Longer time on a shallower wreck ends up giving a similar total run time. So, my ocean dives have been 107 minutes, at the longest.
