Rebreather Comparison Chart

silent running · 16th October 2007, 10:32

Quote: (Originally Posted by caveseeker7)

Phi's guess is as good as any, there are only three PRISMs in the UK afaIk ...
those would be the only ones in Europe I gather.

I do remember the term "volume production model" coming from one of the people,
which pretty much would eliminate the PRISM, too.

Anyway, already PMed Alex that the unit should be included as technically it is in production,
has been for a long time, and has the rare radial scrubber.

Am also curious just how well the unit stands up to CE protocol.
Same is true for the WOB, would have loved to know how it compared to the rest of the lot.
Pete always boasts about both, I know the perceived WOB is very good,
but I want comparable numbers.

Yes indeed Stefan, I too would like to see how the Prism fares on the CE tests. Not likely to happen soon though. Unless I'm mistaken, there's only 2 American made ECCRs currently in production-Optima and Prism-and neither are easily available in the EU. SMI told me that the expense of CE testing is high enough to be prohibitive and of course, the Prism has already been tested rigorously by USN, both manned and unmanned, more than any other civilian off the shelf CCR. And it was interesting to note, as you did elsewhere, that SMI published the USN test data on WOB, scrubber duration and SP accuracy back in 2001, which was recieved with a collective yawn. Maybe it was because it was tested a long time ago, when the few units available for sale each had it's own small, word of mouth following, before anybody had made an issue of the relatively high number of fatalities, before there were any add campaigns and attempts to market CCRs to a wider dive gear market. Who knows.

But I do know that absorbing 344 ltrs of CO2 in an average of 255 minutes before reaching .5% CO2 in 18M of 4.5C water with a 5.5lb radial scrubber is not likely to be surpassed. Nor, given the in-out fine mesh radial scrubber and OTS CLs, is the WOB likely to be improved upon. And I don't see any data on the chart for SP control accuracy.

I'm glad to see Mr. Gurr and Jetsam getting down to brass tacks, but without more details-scrubber weights, description of WOB hydrostatic loads, resistive loads, peak to peak mouth pressures-comparisions will be simplistic at best and misleading at worst.

paulraymaekers · 16th October 2007, 10:39

Quote: (Originally Posted by silent running)

....I'm glad to see Mr. Gurr and Jetsam getting down to brass tacks, but without more details-scrubber weights, description of WOB hydrostatic loads, resistive loads, peak to peak mouth pressures-comparisions will be simplistic at best and misleading at worst.

see pdf in annex
paul

Barrie Law · 16th October 2007, 10:53

Quote: (Originally Posted by paulraymaekers)

see pdf in annex
paul

Hi Paul,

Could you check that attachment it reads error in code??

Ben Field · 16th October 2007, 10:57

Quote: (Originally Posted by silent running)

And I don't see any data on the chart for SP control accuracy.

That would indeed be interesting but how can you compare ECCR to MCCR in that catergory, other than discounting them?

I assume that a correctly setup KISS and rEvo breathing off a machine could be setup to perform almost identically?

Also the results imply the test is run at the same rate for the entire period, an ECCR's trump is surely that it can respond to different breathing rates without the PPO2 changing dramatically, MCCR's would of course suffer in a variable rate test unless some kind of universal method was used for deciding when and for how long the MAV is operated.

Stephane · 16th October 2007, 10:59

Quote: (Originally Posted by Barrie Law)

Hi Paul,

Could you check that attachment it reads error in code??

Works fine here, tested on two different readers (Acrobat and Xpdf).

paulraymaekers · 16th October 2007, 11:11

Quote: (Originally Posted by Barrie Law)

Hi Paul,

Could you check that attachment it reads error in code??

opens perfect in acro reader 6.0!..

paul

can someone of the staff simply put it in the text please?

AD_ward9 · 16th October 2007, 11:19

Quote: (Originally Posted by silent running)

Yes indeed Stefan, I too would like to see how the Prism fares on the CE tests. <snip>

I'm glad to see Mr. Gurr and Jetsam getting down to brass tacks, but without more details-scrubber weights, description of WOB hydrostatic loads, resistive loads, peak to peak mouth pressures-comparisions will be simplistic at best and misleading at worst.

We will publish the full lissajou data if Kevin accepts our offer to do back to back testing so both of us can each claim our data is "independently verified".

We will include the Prism and Meg.

Scrubber measurement is particularly prone to error, no matter how carefully the measurement is done. We know this to our cost. Having two sites get the same number in the same test, will establish a very useful set of reference points.

Alex

Drmike · 16th October 2007, 11:29

Quote: (Originally Posted by bendomatic)

could be the Uzbekistan Peoples Front ,

or it could be the Peoples Front of Uzbekistan! Splitters!

Life of Brian: Scene 7

***Beanie*** · 16th October 2007, 11:48

Quote: (Originally Posted by paulraymaekers)

opens perfect in acro reader 6.0!..

paul

can someone of the staff simply put it in the text please?

calculation of the amount of sorb in the cannisters for the duration test
table 1: reported result of duration test
table 2: reported efficiency of the scrubber
table 3: calculated weight of sorb in cannister during test: according to reported parameters:
CO2 input: 1,6l/min sorb absorbtion capacity 140l CO2/kg
table 4: reported capacity of the cannister (with correction)
table 5: cannister filling % during test
table 6: corrected duration
bear in mind that the correction was done linear:
this is conservative for underfilled cannisters
(duration is more than linear with amount of sorb in the cannister)
comparison chart 1 2 3 4 5 6
duration efficiency
sorb
used capacity fill rate
corrected
duration
(min) (%) (kg) (kg) (%) (min)
sentinel 185 94 2,25 2,2 102,24% 181,0
classic kiss 157 68 2,64 2,6 101,49% 154,7
ouroboros 154 65 2,71 2,7 100,28% 153,6
rEvo 142 66 2,46 2,8 * 87,82% 161,7
inspiration 110 50 2,51 2,5 100,57% 109,4
megalodon 110 50 2,51 2,5 100,57% 109,4
evolution 70 38 2,11 2 105,26% 66,5
sport kiss 65 30 2,48 2,3 107,66% 60,4
optima 60 36 1,90 2,2 ** 86,58% 69,3
* chart specifies 2,9 but it is actually 2,8 (with 2,9 duration would be 167min)
** no direct comparison due to use of EAC
??? Why was the rEvo cannister underfilled during the test ???

***caveseeker7*** · 16th October 2007, 11:50

Here a jpg or the pdf

16th October 2007, 10:32	#51 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,836	Re: Rebreather Comparison Chart Quote: (Originally Posted by caveseeker7) Phi's guess is as good as any, there are only three PRISMs in the UK afaIk ... those would be the only ones in Europe I gather. I do remember the term "volume production model" coming from one of the people, which pretty much would eliminate the PRISM, too. Anyway, already PMed Alex that the unit should be included as technically it is in production, has been for a long time, and has the rare radial scrubber. Am also curious just how well the unit stands up to CE protocol. Same is true for the WOB, would have loved to know how it compared to the rest of the lot. Pete always boasts about both, I know the perceived WOB is very good, but I want comparable numbers. Yes indeed Stefan, I too would like to see how the Prism fares on the CE tests. Not likely to happen soon though. Unless I'm mistaken, there's only 2 American made ECCRs currently in production-Optima and Prism-and neither are easily available in the EU. SMI told me that the expense of CE testing is high enough to be prohibitive and of course, the Prism has already been tested rigorously by USN, both manned and unmanned, more than any other civilian off the shelf CCR. And it was interesting to note, as you did elsewhere, that SMI published the USN test data on WOB, scrubber duration and SP accuracy back in 2001, which was recieved with a collective yawn. Maybe it was because it was tested a long time ago, when the few units available for sale each had it's own small, word of mouth following, before anybody had made an issue of the relatively high number of fatalities, before there were any add campaigns and attempts to market CCRs to a wider dive gear market. Who knows. But I do know that absorbing 344 ltrs of CO2 in an average of 255 minutes before reaching .5% CO2 in 18M of 4.5C water with a 5.5lb radial scrubber is not likely to be surpassed. Nor, given the in-out fine mesh radial scrubber and OTS CLs, is the WOB likely to be improved upon. And I don't see any data on the chart for SP control accuracy. I'm glad to see Mr. Gurr and Jetsam getting down to brass tacks, but without more details-scrubber weights, description of WOB hydrostatic loads, resistive loads, peak to peak mouth pressures-comparisions will be simplistic at best and misleading at worst.
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16th October 2007, 10:53	#53 (permalink)
Barrie Law RebreatherWorld Sponsor Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jun 2005 Location: Ireland Posts: 726	Re: Rebreather Comparison Chart Quote: (Originally Posted by paulraymaekers) see pdf in annex paul Hi Paul, Could you check that attachment it reads error in code?? __________________ Barrie Law Rebreather World Store Supplying the Rebreather World Tel:US +19548403892 Fax:US+19543333792 Tel:EU+442071930496 Fax:EU+442077606344 Mobile+353876880628 Skype:barrielaw Email: barrie@rebreatherworldstore.com
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16th October 2007, 10:57	#54 (permalink)
Ben Field CK+Shearwater Current Rebreather/s: Classic Kiss Other Rebreather/s: Sport Kiss Join Date: Aug 2005 Location: London, England Posts: 1,632	Re: Rebreather Comparison Chart Quote: (Originally Posted by silent running) And I don't see any data on the chart for SP control accuracy. That would indeed be interesting but how can you compare ECCR to MCCR in that catergory, other than discounting them? I assume that a correctly setup KISS and rEvo breathing off a machine could be setup to perform almost identically? Also the results imply the test is run at the same rate for the entire period, an ECCR's trump is surely that it can respond to different breathing rates without the PPO2 changing dramatically, MCCR's would of course suffer in a variable rate test unless some kind of universal method was used for deciding when and for how long the MAV is operated. __________________ Know your PPO2, Pre-breath, Use checklists, Validate cells at 6mtrs, Use pure O2 at or near surface, Use a BOV, Don't dive Solo, Change Slime and Cells as recommended by Manufacturer and RTFM! Beware Fridge Suck! www.hugsac.org.uk
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16th October 2007, 10:59	#55 (permalink)
Stephane Stéphane Acounis Current Rebreather/s: rEvo Other Rebreather/s: rEvo Join Date: Nov 2005 Location: Nantes - France Posts: 773	Re: Rebreather Comparison Chart Quote: (Originally Posted by Barrie Law) Hi Paul, Could you check that attachment it reads error in code?? Works fine here, tested on two different readers (Acrobat and Xpdf). __________________ Stéphane
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16th October 2007, 11:11	#56 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,498	Re: Rebreather Comparison Chart Quote: (Originally Posted by Barrie Law) Hi Paul, Could you check that attachment it reads error in code?? opens perfect in acro reader 6.0!.. paul can someone of the staff simply put it in the text please? __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
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16th October 2007, 11:19	#57 (permalink)
AD_ward9 So much more to learn Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 1,854	Re: Rebreather Comparison Chart Quote: (Originally Posted by silent running) Yes indeed Stefan, I too would like to see how the Prism fares on the CE tests. <snip> I'm glad to see Mr. Gurr and Jetsam getting down to brass tacks, but without more details-scrubber weights, description of WOB hydrostatic loads, resistive loads, peak to peak mouth pressures-comparisions will be simplistic at best and misleading at worst. We will publish the full lissajou data if Kevin accepts our offer to do back to back testing so both of us can each claim our data is "independently verified". We will include the Prism and Meg. Scrubber measurement is particularly prone to error, no matter how carefully the measurement is done. We know this to our cost. Having two sites get the same number in the same test, will establish a very useful set of reference points. Alex Last edited by AD_ward9 : 16th October 2007 at 11:24.
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16th October 2007, 11:29	#58 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,300	Re: Rebreather Comparison Chart Quote: (Originally Posted by bendomatic) could be the Uzbekistan Peoples Front , or it could be the Peoples Front of Uzbekistan! Splitters! Life of Brian: Scene 7 __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
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16th October 2007, 11:48	#59 (permalink)
*Beanie* give a man an inch....... Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,247	Re: Rebreather Comparison Chart Quote: (Originally Posted by paulraymaekers) opens perfect in acro reader 6.0!.. paul can someone of the staff simply put it in the text please? calculation of the amount of sorb in the cannisters for the duration test table 1: reported result of duration test table 2: reported efficiency of the scrubber table 3: calculated weight of sorb in cannister during test: according to reported parameters: CO2 input: 1,6l/min sorb absorbtion capacity 140l CO2/kg table 4: reported capacity of the cannister (with correction) table 5: cannister filling % during test table 6: corrected duration bear in mind that the correction was done linear: this is conservative for underfilled cannisters (duration is more than linear with amount of sorb in the cannister) comparison chart 1 2 3 4 5 6 duration efficiency sorb used capacity fill rate corrected duration (min) (%) (kg) (kg) (%) (min) sentinel 185 94 2,25 2,2 102,24% 181,0 classic kiss 157 68 2,64 2,6 101,49% 154,7 ouroboros 154 65 2,71 2,7 100,28% 153,6 rEvo 142 66 2,46 2,8 * 87,82% 161,7 inspiration 110 50 2,51 2,5 100,57% 109,4 megalodon 110 50 2,51 2,5 100,57% 109,4 evolution 70 38 2,11 2 105,26% 66,5 sport kiss 65 30 2,48 2,3 107,66% 60,4 optima 60 36 1,90 2,2 ** 86,58% 69,3 * chart specifies 2,9 but it is actually 2,8 (with 2,9 duration would be 167min) ** no direct comparison due to use of EAC ??? Why was the rEvo cannister underfilled during the test ??? __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk 0871 242 7808
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