Universal galvanic sensors

[tbone1004]

There is one rebreather that they make adaptor harnesses for that lets you plug a molex cell into a coax breather. People have made it happen.

Wait until the solid state cell comes to market. A little switch on the side that will let you select what sensor it is trying to emulate.

doesn't work like that. They require an external power source and output a digital signal. You could put in a DAC that would do that, but it would have to be a separate board. The DiveCAN rebreathers have an ADC board to convert the analog signal from the sensors to digital for the canbus, but these would communicate directly. You won't get these as a "plug and play" to directly replace an O2 cell.

Do they sell it under a different name for industrial applications?

Poseidon doesn't sell it, nor do they make it.
This company does
PyroScience GmbH

 

[doctormike]

I dunno. I hear a lot from DIY divers telling me that the actual guts (the galvanic sensors) are very similar if not identical. So if it's just the mounting thread and the connector that vary, why can't that be standardized? There are a trillion gadgets out there that use AA batteries. They ALL have exactly the same battery holder, no matter what the gadget does outside of that.

As far as guessing which manufacturer will be in business 20 years from now, that's another reason to standardize. If Eveready goes out of business tomorrow, that would have zero impact on everyone's stuff once Duracell and Rayovac ramp up production to take their customers. If AI and Vandegraph just made a "CCR sensor", of course it would be cheaper because that one design would have ten times as many purchasers as they do now for the JJ sensor and the Meg sensor, etc... In small markets, the price is always higher because initial design costs are spread over fewer customers.

I hear a lot of comments (here and on FB where I started a similar thread) explaining why it would be difficult to do this. But I haven't heard anyone make a case why the current situation is better. So as influencers and keymen in this field (like many of you are), it would make sense to support this cause. Over time, it might well happen if the cell manufacturers and CCR manufacturers get the idea that there is a widely held public desire for a standard.

 

[tbone1004]

@doctormike you're missing the point though, the only difference they have for the Meg is the label that goes on there. It is a stock standard, off the shelf, industrial part number that gets a fancy label so Leon can mark it up. Sure it is a new SKU, but telling the automatic label printers to print a new label on the assembly line doesn't actually change the cost to manufacture. Having unique threads, different size, different connectors, etc. is something that would.
The coax is a standard plug in the industrial world as well.

It would be one thing if they were truly making custom cells for the market, then I would agree with you 100%, but I think the R22D style cell with the molex plug is definitely the defacto cell in rebreathers with the ones using coax being exceptions.

 

[doctormike]

@doctormike you're missing the point though, the only difference they have for the Meg is the label that goes on there. It is a stock standard, off the shelf, industrial part number that gets a fancy label so Leon can mark it up. Sure it is a new SKU, but telling the automatic label printers to print a new label on the assembly line doesn't actually change the cost to manufacture. Having unique threads, different size, different connectors, etc. is something that would.
The coax is a standard plug in the industrial world as well.

It would be one thing if they were truly making custom cells for the market, then I would agree with you 100%, but I think the R22D style cell with the molex plug is definitely the defacto cell in rebreathers with the ones using coax being exceptions.

OK, maybe I'm looking at this from the point of view of a JJ diver who doesn't have the ability to use that standard cell, and is frustrated by the supply line issues. I think that these issues are exacerbated by the smaller market.

So looking at this page, my comments stand for us unlucky divers who dive a JJ, ISC Megalodon, rEvo, Inspiration, Evolution or SF2 rebreathers. Maybe we should ask our manufacturers to switch to the other standard, but that list covers a lot of gear.

 

[tbone1004]

@doctormike I wonder if they changed the sensor compatibility for the new head design or maybe for the pathfinder?, but the PSR-11-39-MD works just fine in my Meg 2.7. The tighter mV range is BS but if they had to change the dimensions then that is on Leon for not designing it around a standard sensor.

Now. I can't stand the cells that my Meg and my Kisskat use which is the standard cell. I think the JJ did it right to use the SMB plug AND to have it on a wire lead which puts less stress on the heads wiring harness which is expensive and a PITA to replace.

Of note, the Revo version just has a tighter mV output from standard, but that will just be batch tolerance limits and while someone like @Dsix36 who dives one will have to clarify, I am pretty sure all of my Revo buddies just use standard cells.

 

[JahJahwarrior]

Is anything stopping you from cutting off the SMB connector from an expired JJ cell and wiring on some molex connectors so you can use the PSR-11-39-MD?

With the o2ptima, you have a wiring harness that connects the molex cells to female banana jacks on the head.

 

[doctormike]

Is anything stopping you from cutting off the SMB connector from an expired JJ cell and wiring on some molex connectors so you can use the PSR-11-39-MD?

With the o2ptima, you have a wiring harness that connects the molex cells to female banana jacks on the head.

Dunno. I know that many of you are very DIR and handy and would feel comfortable doing that. I don't. Maybe that makes me seem less of a diver, but I just don't like the idea of using a cell that the JJ manufacturer specifically recommends not using and MacGyvering it into place. Especially for something as critical as an O2 sensor.

I would rather just be able to buy a product from a manufacturer that is tested and confirmed to work as it is from the factory and put it in the rebreather.

 

[rjack321]

Now. I can't stand the cells that my Meg and my Kisskat use which is the standard cell. I think the JJ did it right to use the SMB plug AND to have it on a wire lead which puts less stress on the heads wiring harness which is expensive and a PITA to replace.

What's wrong with the molex cell? Personally I see way more corroded coax connections, the molex pins to wire insulation joint seems more tolerant of moisture.

So looking at this page, my comments stand for us unlucky divers who dive a JJ, ISC Megalodon, rEvo, Inspiration, Evolution or SF2 rebreathers. Maybe we should ask our manufacturers to switch to the other standard, but that list covers a lot of gear.

The 6x R-22D variants are all the same cell.

Some of those cells fit CCRs which haven't been made in a decade. Good for DGX for selling them, still but they are very dated and the manufacturers are long since out of the CCR business.

Dunno. I know that many of you are very DIR and handy and would feel comfortable doing that. I don't. Maybe that makes me seem less of a diver, but I just don't like the idea of using a cell that the JJ manufacturer specifically recommends not using and MacGyvering it into place. Especially for something as critical as an O2 sensor.

I would rather just be able to buy a product from a manufacturer that is tested and confirmed to work as it is from the factory and put it in the rebreather.

Well you bought a CCR with the most unique O2 cell of all. Talk to Jan about using another type of cell which is more common or available. Or get him to offer/market a coax to molex adapter, there's room for it. I'm sure he thinks his unique cell type is the "best" but also never anticipated manufacture's changing their production runs and not bothering to make his special cell in a global pandemic.

 

[silent running]

While I understand the argument, I think current events are obviously the reason for supply problems. This will pass and hopefully governments will learn from this experience and the next virus will not cause such market disruptions.

In any event, I would not be in favor of standardization as that tends to stop innovation. I’m still hoping to see a needle valve MCCR design which utilizes the high current sensors used in the Prism 1 and MKs. That would enable a passive PPO2 display, which could also share sensor readings with a NERD or similar computer, and would be the simplest and possibly most reliable CCR made yet...

 

[Dsix36]

@doctormike I wonder if they changed the sensor compatibility for the new head design or maybe for the pathfinder?, but the PSR-11-39-MD works just fine in my Meg 2.7. The tighter mV range is BS but if they had to change the dimensions then that is on Leon for not designing it around a standard sensor.

Now. I can't stand the cells that my Meg and my Kisskat use which is the standard cell. I think the JJ did it right to use the SMB plug AND to have it on a wire lead which puts less stress on the heads wiring harness which is expensive and a PITA to replace.

Of note, the Revo version just has a tighter mV output from standard, but that will just be batch tolerance limits and while someone like @Dsix36 who dives one will have to clarify, I am pretty sure all of my Revo buddies just use standard cells.

Correct on the use of standard cells. Of course there are a few individuals we belong to the cult and insist on factory authorized cells.