Mike goes through the new Dive Talk Go

[Wibble]

I asked this same question awhile back- what is so game changing about the solid state cells, besides the need to replace them annually?

I would imagine most people would still carrry a spare with them, like they do with galvanic cells, and you'd still want to verify the cells are working properly during your build and/or pre-dive checks, just like you do with galvanic cells.

I doubt anyone is going to just trust the sensors work before every dive because they turn on, or whatever. That seems antithetical to CCR diving.

Isn't the reason we need 3 (or more) cells and a spare is because galvanic cells are unreliable?

 

[flymolo]

Isn't the reason we need 3 (or more) cells and a spare is because galvanic cells are unreliable?

When solid state sensors become a thing are you only going to run one?

I assume you also have two regulators- is that because regulators are unreliable?

 

[Wibble]

When solid state sensors become a thing are you only going to run one?

I assume you also have two regulators- is that because regulators are unreliable?

ALL critical equipment has a backup. Torches, knives, SMBs, regulators, gas supplies...

Why would cells differ?

The great thing will be eliminating the gross unreliability of galvanic oxygen sensor cells which fail randomly and frequently. Solid State cells offer the prospect of greater reliability. Time, of course, will tell.

 

[broncobowsher]

... IF SSS were such a game changer, how come nobody bought a Poseidon? Why didn't you get one? ...

Because it is a Poseidon. There are a lot of negatives to them. The depth rating battery sales program never worked out as planned. But leaves every owner at the mercy of that special battery to run the rebreather. The automated checklist is well known for throwing false failures.

The solid state sensors (forgot the name of the company, but it has been mentioned in this thread) had an exclusive contract with Poseidon for several years. This stunted growth in other rebreathers. By contract they were not allowed to sell elsewhere. Hindsight that probably wasn't the best for product growth. But without being involved in the contract negotiations, no telling why it was written the way it was.

Now I do know 2 people diving Poseidons, and they are running the solid state cells. The solid state cells have been working good for them.

To counter that on a recent trip with 8 rebreathers the galvanic cells were failing in different rebreathers at different times. It was common to hear someone ask if anyone had any extra cells in the rebreather room. They are the weakest point in modern rebreathers. Failure modes are many. Flat out dead is a nice failure mode to have. But most don't just die, the fade away. Linearity is what I generally have issues with. Get a cell that reads off of the others. But cals out just fine in 100% and is not current limited (I do O2 spikes to make sure they will all read to at least 1.6 PPO2).

What I have seen from solid state O2 cells has been good. Price point is steep, but that should adjust out in time. With the growth of solid state I expect that to take over galvanic cells. That exclusive contract with Poseidon has slowed the growth. But has given the data point that they actually do work and are reliable.

It is nice to see Mike putting them into a new rebreather design. I wonder the the price point is now going to break? I remember seeing my first large high def flat panel TV about 20 years ago. The were about $15k. Now they really have not changed that much but are no longer exclusive items and the price is down to the $1k mark. Hum, solid state cells first out at $1500, regular cells at $100. Look familer? Not saying there will be that much of a price drop, but that is pretty common as technology hits the market in mass.

I can see where solid state drop in for galvanics would progress outside of rebreathers. At work we have a pit in a garage that has an O2 monitor with a galvanic cell in it. While that one gets a few years of service, I could see a solid state making it in there. Because the failure point of that alarm is the sensor as well.

As for Mike making the PPO2 readouts being wireless. Wow! Didn't see that one coming. But if you look at the recent wireless air pressure transmitters, they are pretty good now. The range of transmitting of chest to wrist is pretty short. I've been running wireless and have only had a dropout of a few seconds a couple of times. Not enough to worry about. I will say it would be nice to not have that cord wrapped around my arm.

Mike, if you are reading this, a little more information on that computer please. I don't see it as a tried and true Shearwater. Is KISS making there own computer now?

I still like my rEvo. For my diving, it works good. I do like the 2 scrubber rotation design. I can see a 2 scrubber design working for a chest mount (load one from each end) but the chest mount boom has only taken off in the past couple of years. Nobody has done that yet. And for that comment about not seeing rEvos in caves, a lot of that will go back to a big seller of rEvos back in the day who is currently locked up in federal prison. He soured the rEvo name in cave country. And there are a other rebreathers that are better designed for caves.

 

[Cio]

I asked this same question awhile back- what is so game changing about the solid state cells, besides the need to replace them annually?

I would imagine most people would still carrry a spare with them, like they do with galvanic cells, and you'd still want to verify the cells are working properly during your build and/or pre-dive checks, just like you do with galvanic cells.

I doubt anyone is going to just trust the sensors work before every dive because they turn on, or whatever. That seems antithetical to CCR diving.

Galvanic cells used in rebreathers are not designed for that environment, they are kind of OK but ultimately are a compromise.

SS cells work on a completely different principal and are actually appropriate for the environment. (Big Win) I do not know them intimately, but it is safe to assume that the failure modes are more predictably than galv cells, and they most likely will just crap out and read nothing. The onboard electronics can verify operating conditions and stop broadcasting readings if the conditions are out of spec. (these sensors will fail to give correct readings when the operating conditions are incorrect, i.e. low input voltage to the sensor)

Rated for the enviroment = less prone to failure.
Predictable failure modes = Greater safe outcome if/when a failure occurs.

I have installed these light type sensors in some of the most horrible environments imaginable, never had a failure or one come out of calibration.

I also doubt that people will just trust the sensors because they turn on ( But that is how they work) They never will need calibrate because thats also not how they work. But it is easy to check them in the water or even during a dive so peace of mind is available.

As soon as I could get my hands on them, I'll run them. 2 SS and one galv would be a rock solid combination.

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[flymolo]

the gross unreliability of galvanic oxygen sensor cells which fail randomly and frequently

this is a huge overstatement IMO

 

[Capt Jim Wyatt]

IMO galvanic cells do the job they are advertised to do. They're not perfect, but I'm not sure what piece of dive gear is perfect.

End users must fully understand how they work and how they fail. End users must also know how to detect that a failure is about to occur.

This thread is beginning to wander off-topic.

 

[Wibble]

this is a huge overstatement IMO

Galvanic cells are a huge PITA. The things fail frequently and cost a small fortune. It's by far and away the most fragile part of diving CCR and probably responsible for the vast majority of "can't dive" incidents.

Am personally waiting for a new delivery to replace two of my cells -- recently replaced ones at that.


Well done to Kiss for bringing some innovation into the CCR world. Wireless solid state sensors, yay. Also those unconventional counterlungs.

 

[wetb4igetinthewater]

Let's not forget that not all sensors are the same. I was given AST oxygen sensors when I started out for my rebreather. I had nothing but problems.

Everything changed when I switched to AI sensors that i purchased from DGX.

Having an EE background, I'm very curious about solid state sensors. but I will give it time first as I know for a fact having done external chipset construction analysis for Intel when there outsourced their chipset fabrication, not all manufacturers are the same.

If I still worked there, was rich enough, and was motivated enough, I'd do the same with those sensors.

 

[broncobowsher]

I'll reserve judgement on the counterlungs until I get better view of the attachment setup.
Placement with bailout probably works best with small bailouts. Which is probably a good match for the small scrubber. And the more recreationally bias I am seeing in the design.