Which CCR I think is the best...for me.

**Gill Envy** · 16th December 2005, 17:11

Quote: (Originally Posted by silent running)

.... a CO2 detector would tell you exactly how much CO2 would be in the loop in real time, either with a PPCO2 reading, or a parts per million value. This would be especially usefull for determining when you were approaching an overbreathing situation, say at the begining of a dive/scrubber where the scrubber was just begining to react and you encountered an unexpectedly high workload. IMHO, the greatest potential for a CO2 hit comes from overbreathing, which occurs suddenly.... .-Andy

[quote=...When they develop a CO2 sensor that works I will probably be in line for one as well if that makes diving safer.-Rod[/QUOTE]

Ok, so the Rebreather community generally agrees that 3, even 4 oxygen scensors are a good idea for being doubly, tripply, quadruply shure of your %O2/PO2. It would seem that you guys (Rod and Andy) have two compelling arguments so why not also have redundant CO2/sorb monitoring that would help prevent both CO2 breakthough from over breathing and CO2 breakthrough from burned out sorb. ....My guess is the added expense or lack of compact CO2 sensors is the reason.
And specific to the optima or actually more general than that, is there a temp stick system offered by anyone other than vision that could be added aftermarket...or can the vision temp stick be added to other units.
What i have read so far about the temp stick makes me think that it is worth having to help factor scrubber life, even though it is not fool proof.

***caveseeker7*** · 16th December 2005, 17:22

Breakthrough simply means that CO2 gets past the scrubber into the inhalation side of the loop. That can be sudden due to overbreathing, more or less continiously due to channeling or (depending on the scrubber design more or less slowly) due to exhaustion.

Temperature sensing in the scrubber, where possible, is a good tool to have.
CO2 sensing on the inhalation side would be a neat tool to have, as it would provide actual CO2 data. Ideally, we would want to have both. The temp sensors as an estimated look ahead, the CO sensor to actually know.

In my opinion the temp sensors are like a fuel gauge in a car. While it tells you your fuel level, you don't know if the fuel actually gets to the engine. Likewise, no one would replace the fuel tank gauge with a fuel sensor in the the motor and accept getting notified when the car is out of gas.

Tom Rose's idea of sampling inside the scrubber seems like a great tool to have, as you would get actual CO2 data before the scrubber is actually completely exhausted. I truly his concept will work out in reality and turn into an affordable, reliable CO2 monitoring and warning system.

**Gill Envy** · 16th December 2005, 21:44

the good news is that i just talked to Rudi of IANTD, the one who gave the demo. I asked him if I understood correctly that there would be a canister insert for granular scrubber, as i have not been able to verify this with Dive Rite. He told me there was one sitting in front of him on his desk right now, a stainless steel insert and it will be available in march for around $200. It will have a slightly reduced duration, he said probably 2 1/2 hrs instead of 3...and the cost per cartridge of the micropore insert is likely to come down as economy of scale is reached in production levels. The granules are likely a good choice for those times when for whatever reason you don’t need the full capacity of the cartridge and will be disposing of the sorb after one relatively short use, like when you just want to do one dive and won’t be doing another within a few days.
All this renewed my positive feelings for the Optima, as the high cost of the micropore canister was a deal breaker, smelled fishy, sounded like a captive market kind of thing that I didn't want to get caught in. I can now say with confidence after much consideration that the optima remains my number one pick, though I will still be looking into the meg, and who knows, things could change. I expect to throw down and buy a unit within a few months. I have also been reading up on the benefits of the canister and if the cost comes down a bit, it looks like it certainly has it's applications. It apparently shows promise for recovering from a flood without forcing bail out, less likely to cause caustic cocktail and eliminates the possibility of channeling. The canister does not require tamping or pouring of granules and looks like the micropores would give you more consistent reactant field. I like that for the times when we are in the rain camping, not in a dry indoor envrionment, the scrubber replancement is sealed and a synch to swap and thus less likely to take on water.
hey, again, thanks to everyone for being so integral in helping me make an educated choice...in the end, I think I will be much less likely to make a choice I regrett because of this Forum.
oh, and one last thing, Rudi mentioned that they are in the process of making a full back up rebreather for bail out...very interesting!

Explorer · 16th December 2005, 22:03

Gill,

Congrads and looking forward to pics of your Optima christmas present.

01RMB · 16th December 2005, 22:10

Quote: (Originally Posted by caveseeker7)

In my opinion the temp sensors are like a fuel gauge in a car. While it tells you your fuel level, you don't know if the fuel actually gets to the engine. Likewise, no one would replace the fuel tank gauge with a fuel sensor in the the motor and accept getting notified when the car is out of gas.

Gill
Stefan's analogy about the fuel gauge and fuel sensor is exactly how I feel about the temp stik and CO2 monitor. (Stefan - well done, I was trying to write something similar last night but was too tired after a real bad day).
The argument over the temp stik and CO2 monitors is like

with a temp stik and not worth getting into.

As to why CO2 sensors are not on rebreathers - CO2 monitor systems that work in the hot, moist and variable environment of a rebreather loop do not currently exist to the very fine level between what is okay and what is deadly. In the future they will be a great asset to safety since the CO2 monitors will be good to warn if too much CO2 gets through or past the scrubber for any reason.

As far as retrofitting a temperature sensor to a rebreather - AFAIK The only manufacturer that currently offers one is APD on the Vision electronics package. As the largest producer of rebreathers they have put the money into R&D and have developed a total package. From what I understand the trick was in the interpretation of the data from the sensors rather than just use it as a thermometer. The information is well presented on the Vision handset.

Others I am sure will offer something similar in the future - innovation is quickly followed by imitation! Which is not a bad thing because it will lead to improvements in rebreathers and increased safety. The various scrubber designs will cause problems with this though since it would probably need to be specific to each scrubber design.

I at first was sceptical about the benefits of the temp stik (just throw the sorb out when the time raeds 2 hours) but after meeting and talking with Martin Parker I was convinced of it's benefits and put up the extra money for the option. No regrets - it was worth the $$ since I would otherwise be throwing away a lot more sorb that still had plenty of good life left. In my experience I am getting at least double the life.

Sorry if this is leading off topic. There are benefits of each rebreather design. As the market matures and volumes increase a lot of the benefits will flow over to the other vendor's designs. Each step leads to improvement in rebreathers and safety.

Good luck with your choice - and that is the great thing - there is now a good choice with some great products available.

***ScubaDadMiami*** · 17th December 2005, 04:05

Quote:

I use the temp stik to show how the scrubber is being used and to give me an idea of when to change. . . . The benefit of the temp stik over something like the CO2 sensors being talked about is that the scrubber monitor gives you warning of the scrubber getting used, when it is close to time to get off the loop and when you must get off the loop as opposed to the CO2 monitor which will only tell you when you have breakthrough and must get off the loop.

Quote:

. . . the CO2 tempstick points you made are easy to disagree with. First off, a CO2 detector would tell you exactly how much CO2 would be in the loop in real time, either with a PPCO2 reading, or a parts per million value. This would be especially usefull for determining when you were approaching an overbreathing situation, say at the begining of a dive/scrubber where the scrubber was just begining to react and you encountered an unexpectedly high workload. IMHO, the greatest potential for a CO2 hit comes from overbreathing, which occurs suddenly. This as opposed to breakthrough, which occurs gradually over a predictable length of time, meaning the scrubber duration. The temp stick might eventually let you know that the scrubber was being overbreathed, but my guess is it would be way too late to be of use in such a situation. As for getting maximum life out of a scrubber, the tempstick may be of some use, but there are those who argue that temp/temp fronts and actual CO2 removal do not always match up. So I'm not sure how much use the TS is when we all have a dive comp or watch which tells us how much time has passed as a given.

What about putting both in a unit? Wouldn't this cover both points? It would cost a lot, I know.

16th December 2005, 17:11	#61 (permalink)
Gill Envy Shearwater Copis Diver Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,302	Re: Which CCR I think is the best...for me. Quote: (Originally Posted by silent running) .... a CO2 detector would tell you exactly how much CO2 would be in the loop in real time, either with a PPCO2 reading, or a parts per million value. This would be especially usefull for determining when you were approaching an overbreathing situation, say at the begining of a dive/scrubber where the scrubber was just begining to react and you encountered an unexpectedly high workload. IMHO, the greatest potential for a CO2 hit comes from overbreathing, which occurs suddenly.... .-Andy [quote=...When they develop a CO2 sensor that works I will probably be in line for one as well if that makes diving safer.-Rod[/QUOTE] Ok, so the Rebreather community generally agrees that 3, even 4 oxygen scensors are a good idea for being doubly, tripply, quadruply shure of your %O2/PO2. It would seem that you guys (Rod and Andy) have two compelling arguments so why not also have redundant CO2/sorb monitoring that would help prevent both CO2 breakthough from over breathing and CO2 breakthrough from burned out sorb. ....My guess is the added expense or lack of compact CO2 sensors is the reason. And specific to the optima or actually more general than that, is there a temp stick system offered by anyone other than vision that could be added aftermarket...or can the vision temp stick be added to other units. What i have read so far about the temp stick makes me think that it is worth having to help factor scrubber life, even though it is not fool proof. __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°>
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16th December 2005, 17:22	#62 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,435	Re: Breakthrough Breakthrough simply means that CO2 gets past the scrubber into the inhalation side of the loop. That can be sudden due to overbreathing, more or less continiously due to channeling or (depending on the scrubber design more or less slowly) due to exhaustion. Temperature sensing in the scrubber, where possible, is a good tool to have. CO2 sensing on the inhalation side would be a neat tool to have, as it would provide actual CO2 data. Ideally, we would want to have both. The temp sensors as an estimated look ahead, the CO sensor to actually know. In my opinion the temp sensors are like a fuel gauge in a car. While it tells you your fuel level, you don't know if the fuel actually gets to the engine. Likewise, no one would replace the fuel tank gauge with a fuel sensor in the the motor and accept getting notified when the car is out of gas. Tom Rose's idea of sampling inside the scrubber seems like a great tool to have, as you would get actual CO2 data before the scrubber is actually completely exhausted. I truly his concept will work out in reality and turn into an affordable, reliable CO2 monitoring and warning system. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.'!"
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16th December 2005, 21:44	#63 (permalink)
Gill Envy Shearwater Copis Diver Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,302	Re: Which CCR I think is the best...for me. the good news is that i just talked to Rudi of IANTD, the one who gave the demo. I asked him if I understood correctly that there would be a canister insert for granular scrubber, as i have not been able to verify this with Dive Rite. He told me there was one sitting in front of him on his desk right now, a stainless steel insert and it will be available in march for around $200. It will have a slightly reduced duration, he said probably 2 1/2 hrs instead of 3...and the cost per cartridge of the micropore insert is likely to come down as economy of scale is reached in production levels. The granules are likely a good choice for those times when for whatever reason you don’t need the full capacity of the cartridge and will be disposing of the sorb after one relatively short use, like when you just want to do one dive and won’t be doing another within a few days. All this renewed my positive feelings for the Optima, as the high cost of the micropore canister was a deal breaker, smelled fishy, sounded like a captive market kind of thing that I didn't want to get caught in. I can now say with confidence after much consideration that the optima remains my number one pick, though I will still be looking into the meg, and who knows, things could change. I expect to throw down and buy a unit within a few months. I have also been reading up on the benefits of the canister and if the cost comes down a bit, it looks like it certainly has it's applications. It apparently shows promise for recovering from a flood without forcing bail out, less likely to cause caustic cocktail and eliminates the possibility of channeling. The canister does not require tamping or pouring of granules and looks like the micropores would give you more consistent reactant field. I like that for the times when we are in the rain camping, not in a dry indoor envrionment, the scrubber replancement is sealed and a synch to swap and thus less likely to take on water. hey, again, thanks to everyone for being so integral in helping me make an educated choice...in the end, I think I will be much less likely to make a choice I regrett because of this Forum. oh, and one last thing, Rudi mentioned that they are in the process of making a full back up rebreather for bail out...very interesting! __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°> Last edited by Gill Envy : 16th December 2005 at 22:09.
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16th December 2005, 22:03	#64 (permalink)
Explorer I will teach you a..... Current Rebreather/s: Evolution Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Alberta, Canada Posts: 762	Re: Which CCR I think is the best...for me. Gill, Congrads and looking forward to pics of your Optima christmas present. __________________ REALLY FRICKIN' TRAIN WRECKED.....
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16th December 2005, 22:10	#65 (permalink)
01RMB Evolving Current Rebreather/s: Evolution Other Rebreather/s: Join Date: May 2005 Location: Brisbane, Australia Posts: 192	Re: Breakthrough Quote: (Originally Posted by caveseeker7) In my opinion the temp sensors are like a fuel gauge in a car. While it tells you your fuel level, you don't know if the fuel actually gets to the engine. Likewise, no one would replace the fuel tank gauge with a fuel sensor in the the motor and accept getting notified when the car is out of gas. Gill Stefan's analogy about the fuel gauge and fuel sensor is exactly how I feel about the temp stik and CO2 monitor. (Stefan - well done, I was trying to write something similar last night but was too tired after a real bad day). The argument over the temp stik and CO2 monitors is like with a temp stik and not worth getting into. As to why CO2 sensors are not on rebreathers - CO2 monitor systems that work in the hot, moist and variable environment of a rebreather loop do not currently exist to the very fine level between what is okay and what is deadly. In the future they will be a great asset to safety since the CO2 monitors will be good to warn if too much CO2 gets through or past the scrubber for any reason. As far as retrofitting a temperature sensor to a rebreather - AFAIK The only manufacturer that currently offers one is APD on the Vision electronics package. As the largest producer of rebreathers they have put the money into R&D and have developed a total package. From what I understand the trick was in the interpretation of the data from the sensors rather than just use it as a thermometer. The information is well presented on the Vision handset. Others I am sure will offer something similar in the future - innovation is quickly followed by imitation! Which is not a bad thing because it will lead to improvements in rebreathers and increased safety. The various scrubber designs will cause problems with this though since it would probably need to be specific to each scrubber design. I at first was sceptical about the benefits of the temp stik (just throw the sorb out when the time raeds 2 hours) but after meeting and talking with Martin Parker I was convinced of it's benefits and put up the extra money for the option. No regrets - it was worth the $$ since I would otherwise be throwing away a lot more sorb that still had plenty of good life left. In my experience I am getting at least double the life. Sorry if this is leading off topic. There are benefits of each rebreather design. As the market matures and volumes increase a lot of the benefits will flow over to the other vendor's designs. Each step leads to improvement in rebreathers and safety. Good luck with your choice - and that is the great thing - there is now a good choice with some great products available. __________________ Cheers Rod
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17th December 2005, 04:05	#66 (permalink)
*ScubaDadMiami* Moderator Current Rebreather/s: Optima Other Rebreather/s: Join Date: Sep 2005 Location: Florida, USA Posts: 2,068	Re: Which CCR I think is the best...for me. Quote: I use the temp stik to show how the scrubber is being used and to give me an idea of when to change. . . . The benefit of the temp stik over something like the CO2 sensors being talked about is that the scrubber monitor gives you warning of the scrubber getting used, when it is close to time to get off the loop and when you must get off the loop as opposed to the CO2 monitor which will only tell you when you have breakthrough and must get off the loop. Quote: . . . the CO2 tempstick points you made are easy to disagree with. First off, a CO2 detector would tell you exactly how much CO2 would be in the loop in real time, either with a PPCO2 reading, or a parts per million value. This would be especially usefull for determining when you were approaching an overbreathing situation, say at the begining of a dive/scrubber where the scrubber was just begining to react and you encountered an unexpectedly high workload. IMHO, the greatest potential for a CO2 hit comes from overbreathing, which occurs suddenly. This as opposed to breakthrough, which occurs gradually over a predictable length of time, meaning the scrubber duration. The temp stick might eventually let you know that the scrubber was being overbreathed, but my guess is it would be way too late to be of use in such a situation. As for getting maximum life out of a scrubber, the tempstick may be of some use, but there are those who argue that temp/temp fronts and actual CO2 removal do not always match up. So I'm not sure how much use the TS is when we all have a dive comp or watch which tells us how much time has passed as a given. What about putting both in a unit? Wouldn't this cover both points? It would cost a lot, I know. __________________ Howard Packer IANTD CCR Instructor Miami Beach, Florida CCRDiveTraining.com Last edited by ScubaDadMiami : 17th December 2005 at 04:07.
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