ISC posts test data

womble · 31st March 2008, 21:31

It would be good to have a response from Jakub aka lof from golem gear about these results.

I know there was talk of the GG scrubber being tested, afaik these results havent been published. . . . unless anyone knows different.

babar · 1st April 2008, 09:48

The other thing about WOB is that we are very poor judges of it. This was heavily emphasized by the guys at NEDU, during the DAN tech conference. We (humans) are poor judges of WOB. They demonstrated under test conditions that fit divers would report good work of breathing, and then go on to retain co2 and pass out. This is why objective tests of WOB are so important.

Quote: (Originally Posted by silent running)

Hello Richie, under normal, favorable dive conditions most of the units for sale these days have acceptable WOB. When I say favorable I mean no hard work and the unit is trimed out to it's optimal orientation. By way of example, when I spoke to one of the Navy guys at the NEDU about the MK16 they had on display, he reminded me that the unit breathes great in an upright position, which is the position one needs to be in for diffusing mines. He then went on to say that it breathed poorly in a horizontal position.

And given that CO2 hits always start with our bodies retaining CO2 and how hard it is to get rid of the CO2 once we begin retaining it, WOB becomes critical when we are working hard and expecially at depth. And differences in WOB that may seem small in favorable conditions will be amplified in bad conditions, like the ones I sometimes find myself doing exploratory dives in places like Indonesia. And as I said recently, I needed all the help I could get trying to fight my way up after getting blown down to 75M in a 3 knot down diving at Banta Island in Komodo... _Andy

diverklondike · 1st April 2008, 12:51

Quote: (Originally Posted by AD_ward9)

Each of the standards do cover the relevant and important points: EN14143, NORSOK U101, the US Naval 1994 Procurement spec etc.

The main item missing is the EN61508 compliance.

Returning to the breathing parameters, the devil is in the small print: ensuring test conditions are the same so comparisons can be made. EN14143 does a reasonable job, and companies like CCR Ltd have stuck to it well. The problem with the ISC numbers is that neither the HSE nor ISC read the spec carefully enough, so did the tests at the wrong depth. With major errors like that, one suspects others, such as ensuring the breathing machine is set to the correct waveform and is in calibration. I am very keen for companies to publish data, it is a big step forward in safety. What I would like to try and achieve here is simply create awareness of what to look out for when doing tests, so the test results are valid and not disputed.

On Diverreb's question: it is not like computer X is 50% faster than computer Y. It is computer X is unsafe and will kill you under specific circumstances, whereas computer Y will not. WOB, scrubber endurance etc, are very basic safety measurements. All equipment should comply with minimum standards: EN14143 is a minimum safety standard, not a guarantee. The first stage in getting compliance is for companies to test what they are selling (or better still, test what they are designing). ISC made a good step forward, as has Paul with the rEvo. It is a complex area, so sharing information on how to do this properly and what errors to look out for should make it easier for companies to go down this route.

On Paul's post below. Good. So 3.15J/L is a pass point from the WOB issue.

Alex

Alex,

Can you list what the a key items are out of each. I think part of the challenge here is getting people to understand this is the complexity, hence the reason that am asking for this. If we can boil it down to a handful of things that people can understand, MFGs won't be able to hide behind the complexity as easily.

For example:

EN14143
Test A
Test B
NORSOK U101
Test C
Test D
US Naval 1994 Procurement Spec
Test E
Test F
Test G
EN61508
Test H
Test I

The goal from my stand point is pure simplification.... I understand as you mention that the devil is in the small print but we do need to start somewhere.

I agree that MFGs starting to post data is a good thing but as we have seen in this example, they do everything they can to aggresively spin it for their benifit. If we had this simplified list, at least we could start putting things in a better perspective from the consumer point of view. For example we could approach Leon, Kevin J, Martin Parker, Paul, Kevin Gurr, Lamar etc... in this public forum and say... Here is a list of what we feel are key test points, have you tested your units for these and or do you plan to do so. They can simply state....

Yes we have and the result was... "X"
Yes we have but are not ready to share this information at this time since we are working to improve our results.
No we have not but plan to at some future date
No we have not and don't plan to because we don't feel it's a relevent test.
Our stance is that we do not share this kind of data with the public.

This little exercise along with the effort that Mark Chase has under way would go a long way to clearing the fog...

If it can't be done it can't be done...

Paul... I would be very interested in your thoughts on this since you so active on the board and open with your discussion.

Just my two cents.

M

silent running · 1st April 2008, 17:39

Quote: (Originally Posted by babar)

The other thing about WOB is that we are very poor judges of it. This was heavily emphasized by the guys at NEDU, during the DAN tech conference. We (humans) are poor judges of WOB. They demonstrated under test conditions that fit divers would report good work of breathing, and then go on to retain co2 and pass out. This is why objective tests of WOB are so important.

Yes babar, proper standardized tests are very important in evaluating WOB. And yes, sometimes we can be poor judges of WOB and because of the insidious nature of CO2, we can be right on the verge of passing out and barely notice. But I doubt anybody needs a breathing machine to tell them when the work of breathing really becomes work. I certainly didn't need one to tell me that the Dolphin breathed significantly worse than the Prism. Nor do we need a breathing machine to tell us things that we already know, like the fact that thicker flapper valves will increase WOB as will longer grain boundaries in the scrubber and moving the CLs away from the body and lungs...

PaulTG2 · 1st April 2008, 18:02

Quote: (Originally Posted by silent running)

...But I doubt anybody needs a breathing machine to tell them when the work of breathing really becomes work....

Yes, but coming to this conclusion when you have a problem to solve at 300' probably isn't the best place. That's why real-world information would be helpful. The stats in the ISC report provides a way to evaluate which has lower WOB at the test points, but how does that translate into real-world at various depths is the valuable answer.

It reminds me of stereo manufacturers that promoted their systems over others based on specification differences that no human ear could distinguish or speakers could reproduce. Technical superior without any value.

In the end the question still is, HOW does that impact me -- what are the practical differences. I don't think we have answers for that yet.

-p

silent running · 1st April 2008, 20:16

Quote: (Originally Posted by PaulTG2)

In the end the question still is, HOW does that impact me -- what are the practical differences. I don't think we have answers for that yet.

-p

Hi Paul, one practicality is that you need all the help you can get during periods of maximum exertion on CCR. WOB increases at higher RMVs and at depth, so starting off with the lowest possible WOB is important part of avoiding a build up of CO2 in the body.

lof · 2nd April 2008, 03:37

Quote: (Originally Posted by womble)

It would be good to have a response from Jakub aka lof from golem gear about these results.

I know there was talk of the GG scrubber being tested, afaik these results havent been published. . . . unless anyone knows different.

Sorry for delayed response. Just got back from BTS and had to deal with pile of orders. Second half of last week was insane with sales of BOVs and scrubbers

I am not sure what and how ISC measured as I did not have time to go over their data in detail. We have identified the issue with the one way valves a while ago (thanks to Paul for initial hint) and started using the Drager valves. The Vario models come with them already. The retrofit valves for Standard models are being manufactured as we speak (the holder size is different).
Below are results from OUR preliminary tests on complete HH CCR to CE standards:
(Sofnolime 8-12Mesh, 40 RMV, 40°F, Rebreather ADV Gas Add,RPitch Orientation, 1.6 CO2,150FSW, Large Scrubber, 27 rib, 2L x 20bpm, 45° Reverse pitch,no EV, calibrated to 0.497% and N2)
We will publish complete results once they are finished - there is a lot more to do.

***jradomski*** · 2nd April 2008, 05:17

Quote: (Originally Posted by lof)

Sorry for delayed response. Just got back from BTS and had to deal with pile of orders. Second half of last week was insane with sales of BOVs and scrubbers

I am not sure what and how ISC measured as I did not have time to go over their data in detail. We have identified the issue with the one way valves a while ago (thanks to Paul for initial hint) and started using the Drager valves. The Vario models come with them already. The retrofit valves for Standard models are being manufactured as we speak (the holder size is different).
Below are results from OUR preliminary tests on complete HH CCR to CE standards:
(Sofnolime 8-12Mesh, 40 RMV, 40°F, Rebreather ADV Gas Add,RPitch Orientation, 1.6 CO2,150FSW, Large Scrubber, 27 rib, 2L x 20bpm, 45° Reverse pitch,no EV, calibrated to 0.497% and N2)
We will publish complete results once they are finished - there is a lot more to do.

JAKUB,
Why was it tested at 45m instead of 40m??

AD_ward9 · 2nd April 2008, 07:06

It is not as simple as that.

All the standards you mention, measure the same things: WOB, hydrostatic imbalance, CO2 retention, PPO2 control, scrubber endurance, mechanical robustness, etc. The devil is in the details.

There are differences in the way measurements are made between the various standards. For example, in PPO2 and WOB tests NORSOK covers metabolic rates from 0.3 l/min to 4.5l/min, whereas EN14143 covers only 1.78l/min. Lissajous go in opposite direction in En14143 compared to everywhere else. There is the issue of Sine flow or sine pressure (sine flow is 3.3J/L with the EN14143 calibration orifice but produces a distorted elipsoid Lissajou, sine pressure produces a nice Lissajou but has a WOB of 3.98J/L under the same conditions).

I suggest for comparative WOB figures, people stick to En14143 conditions. It is then a very simple test at just under 40msw (5 bar absolute pressure), using 75L/min RMV with a 3 litre stroke, using air. The calibration is done specifically at 6 bar absolute using 62.5L/min and 2.5litre stroke using air.

I will try and post the figures I promised today: the files were too big yesterday, so I need to cut out the figures and compress them.

Just a reminder for everyone: if you post any WOB claims, no-one should believe a thing unless you post the Lissajou of the calibration orifice measured on the same system at 6 bar absolute (about 50msw). There is too much scope for error unless you show the system it was measured on is calibrated: words like "Normalised" WOB make me very suspicious.

Alex

Quote: (Originally Posted by diverklondike)

Alex,

Can you list what the a key items are out of each. I think part of the challenge here is getting people to understand this is the complexity, hence the reason that am asking for this. If we can boil it down to a handful of things that people can understand, MFGs won't be able to hide behind the complexity as easily.

For example:

EN14143
Test A
Test B
NORSOK U101
Test C
<snip>

M

J. V. · 2nd April 2008, 08:13

Quote:

The retrofit valves for Standard models are being manufactured as we speak (the holder size is different)

Hi Jakub,
Thank you to inform us when it will be available.

31st March 2008, 21:31	#131 (permalink)
womble RBW Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2006 Location: UK Posts: 201	Re: ISC posts test data It would be good to have a response from Jakub aka lof from golem gear about these results. I know there was talk of the GG scrubber being tested, afaik these results havent been published. . . . unless anyone knows different. __________________ "What could possibly go wrong?? . . "
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1st April 2008, 09:48	#132 (permalink)
babar Curmudgeon Current Rebreather/s: Evolution Other CCR Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Sport Kiss Other CCR Join Date: Apr 2005 Location: Southern California Posts: 425	Re: ISC posts test data The other thing about WOB is that we are very poor judges of it. This was heavily emphasized by the guys at NEDU, during the DAN tech conference. We (humans) are poor judges of WOB. They demonstrated under test conditions that fit divers would report good work of breathing, and then go on to retain co2 and pass out. This is why objective tests of WOB are so important. Quote: (Originally Posted by silent running) Hello Richie, under normal, favorable dive conditions most of the units for sale these days have acceptable WOB. When I say favorable I mean no hard work and the unit is trimed out to it's optimal orientation. By way of example, when I spoke to one of the Navy guys at the NEDU about the MK16 they had on display, he reminded me that the unit breathes great in an upright position, which is the position one needs to be in for diffusing mines. He then went on to say that it breathed poorly in a horizontal position. And given that CO2 hits always start with our bodies retaining CO2 and how hard it is to get rid of the CO2 once we begin retaining it, WOB becomes critical when we are working hard and expecially at depth. And differences in WOB that may seem small in favorable conditions will be amplified in bad conditions, like the ones I sometimes find myself doing exploratory dives in places like Indonesia. And as I said recently, I needed all the help I could get trying to fight my way up after getting blown down to 75M in a 3 knot down diving at Banta Island in Komodo... _Andy __________________ Babar Evolution Plus Sport kiss
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1st April 2008, 12:51	#133 (permalink)
diverklondike RBW Member Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Oct 2005 Location: Delaware, USA Posts: 1,714	Re: ISC posts test data Quote: (Originally Posted by AD_ward9) Each of the standards do cover the relevant and important points: EN14143, NORSOK U101, the US Naval 1994 Procurement spec etc. The main item missing is the EN61508 compliance. Returning to the breathing parameters, the devil is in the small print: ensuring test conditions are the same so comparisons can be made. EN14143 does a reasonable job, and companies like CCR Ltd have stuck to it well. The problem with the ISC numbers is that neither the HSE nor ISC read the spec carefully enough, so did the tests at the wrong depth. With major errors like that, one suspects others, such as ensuring the breathing machine is set to the correct waveform and is in calibration. I am very keen for companies to publish data, it is a big step forward in safety. What I would like to try and achieve here is simply create awareness of what to look out for when doing tests, so the test results are valid and not disputed. On Diverreb's question: it is not like computer X is 50% faster than computer Y. It is computer X is unsafe and will kill you under specific circumstances, whereas computer Y will not. WOB, scrubber endurance etc, are very basic safety measurements. All equipment should comply with minimum standards: EN14143 is a minimum safety standard, not a guarantee. The first stage in getting compliance is for companies to test what they are selling (or better still, test what they are designing). ISC made a good step forward, as has Paul with the rEvo. It is a complex area, so sharing information on how to do this properly and what errors to look out for should make it easier for companies to go down this route. On Paul's post below. Good. So 3.15J/L is a pass point from the WOB issue. Alex Alex, Can you list what the a key items are out of each. I think part of the challenge here is getting people to understand this is the complexity, hence the reason that am asking for this. If we can boil it down to a handful of things that people can understand, MFGs won't be able to hide behind the complexity as easily. For example: EN14143 Test A Test B NORSOK U101 Test C Test D US Naval 1994 Procurement Spec Test E Test F Test G EN61508 Test H Test I The goal from my stand point is pure simplification.... I understand as you mention that the devil is in the small print but we do need to start somewhere. I agree that MFGs starting to post data is a good thing but as we have seen in this example, they do everything they can to aggresively spin it for their benifit. If we had this simplified list, at least we could start putting things in a better perspective from the consumer point of view. For example we could approach Leon, Kevin J, Martin Parker, Paul, Kevin Gurr, Lamar etc... in this public forum and say... Here is a list of what we feel are key test points, have you tested your units for these and or do you plan to do so. They can simply state.... Yes we have and the result was... "X" Yes we have but are not ready to share this information at this time since we are working to improve our results. No we have not but plan to at some future date No we have not and don't plan to because we don't feel it's a relevent test. Our stance is that we do not share this kind of data with the public. This little exercise along with the effort that Mark Chase has under way would go a long way to clearing the fog... If it can't be done it can't be done... Paul... I would be very interested in your thoughts on this since you so active on the board and open with your discussion. Just my two cents. M Last edited by diverklondike : 1st April 2008 at 13:09.
(Offline)

1st April 2008, 17:39	#134 (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: 1,873	Re: ISC posts test data Quote: (Originally Posted by babar) The other thing about WOB is that we are very poor judges of it. This was heavily emphasized by the guys at NEDU, during the DAN tech conference. We (humans) are poor judges of WOB. They demonstrated under test conditions that fit divers would report good work of breathing, and then go on to retain co2 and pass out. This is why objective tests of WOB are so important. Yes babar, proper standardized tests are very important in evaluating WOB. And yes, sometimes we can be poor judges of WOB and because of the insidious nature of CO2, we can be right on the verge of passing out and barely notice. But I doubt anybody needs a breathing machine to tell them when the work of breathing really becomes work. I certainly didn't need one to tell me that the Dolphin breathed significantly worse than the Prism. Nor do we need a breathing machine to tell us things that we already know, like the fact that thicker flapper valves will increase WOB as will longer grain boundaries in the scrubber and moving the CLs away from the body and lungs...
(Offline)

1st April 2008, 18:02	#135 (permalink)
PaulTG2 RBW Member Current Rebreather/s: Megalodon Classic Kiss Other Rebreather/s: Sport Kiss Join Date: Mar 2006 Location: Virginia, USA Posts: 517	Re: ISC posts test data Quote: (Originally Posted by silent running) ...But I doubt anybody needs a breathing machine to tell them when the work of breathing really becomes work.... Yes, but coming to this conclusion when you have a problem to solve at 300' probably isn't the best place. That's why real-world information would be helpful. The stats in the ISC report provides a way to evaluate which has lower WOB at the test points, but how does that translate into real-world at various depths is the valuable answer. It reminds me of stereo manufacturers that promoted their systems over others based on specification differences that no human ear could distinguish or speakers could reproduce. Technical superior without any value. In the end the question still is, HOW does that impact me -- what are the practical differences. I don't think we have answers for that yet. -p
(Offline)

1st April 2008, 20:16	#136 (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: 1,873	Re: ISC posts test data Quote: (Originally Posted by PaulTG2) In the end the question still is, HOW does that impact me -- what are the practical differences. I don't think we have answers for that yet. -p Hi Paul, one practicality is that you need all the help you can get during periods of maximum exertion on CCR. WOB increases at higher RMVs and at depth, so starting off with the lowest possible WOB is important part of avoiding a build up of CO2 in the body.
(Offline)

2nd April 2008, 05:17	#138 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,113	Re: ISC posts test data Quote: (Originally Posted by lof) Sorry for delayed response. Just got back from BTS and had to deal with pile of orders. Second half of last week was insane with sales of BOVs and scrubbers I am not sure what and how ISC measured as I did not have time to go over their data in detail. We have identified the issue with the one way valves a while ago (thanks to Paul for initial hint) and started using the Drager valves. The Vario models come with them already. The retrofit valves for Standard models are being manufactured as we speak (the holder size is different). Below are results from OUR preliminary tests on complete HH CCR to CE standards: (Sofnolime 8-12Mesh, 40 RMV, 40°F, Rebreather ADV Gas Add,RPitch Orientation, 1.6 CO2,150FSW, Large Scrubber, 27 rib, 2L x 20bpm, 45° Reverse pitch,no EV, calibrated to 0.497% and N2) We will publish complete results once they are finished - there is a lot more to do. JAKUB, Why was it tested at 45m instead of 40m?? __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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2nd April 2008, 07:06	#139 (permalink)
AD_ward9 RBW Member Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 2,011	Re: ISC posts test data It is not as simple as that. All the standards you mention, measure the same things: WOB, hydrostatic imbalance, CO2 retention, PPO2 control, scrubber endurance, mechanical robustness, etc. The devil is in the details. There are differences in the way measurements are made between the various standards. For example, in PPO2 and WOB tests NORSOK covers metabolic rates from 0.3 l/min to 4.5l/min, whereas EN14143 covers only 1.78l/min. Lissajous go in opposite direction in En14143 compared to everywhere else. There is the issue of Sine flow or sine pressure (sine flow is 3.3J/L with the EN14143 calibration orifice but produces a distorted elipsoid Lissajou, sine pressure produces a nice Lissajou but has a WOB of 3.98J/L under the same conditions). I suggest for comparative WOB figures, people stick to En14143 conditions. It is then a very simple test at just under 40msw (5 bar absolute pressure), using 75L/min RMV with a 3 litre stroke, using air. The calibration is done specifically at 6 bar absolute using 62.5L/min and 2.5litre stroke using air. I will try and post the figures I promised today: the files were too big yesterday, so I need to cut out the figures and compress them. Just a reminder for everyone: if you post any WOB claims, no-one should believe a thing unless you post the Lissajou of the calibration orifice measured on the same system at 6 bar absolute (about 50msw). There is too much scope for error unless you show the system it was measured on is calibrated: words like "Normalised" WOB make me very suspicious. Alex Quote: (Originally Posted by diverklondike) Alex, Can you list what the a key items are out of each. I think part of the challenge here is getting people to understand this is the complexity, hence the reason that am asking for this. If we can boil it down to a handful of things that people can understand, MFGs won't be able to hide behind the complexity as easily. For example: EN14143 Test A Test B NORSOK U101 Test C <snip> M Last edited by AD_ward9 : 2nd April 2008 at 07:22.
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2nd April 2008, 08:13	#140 (permalink)
J. V. RBW Member Current Rebreather/s: rEvo Other Rebreather/s: Not Bought Yet rEvo Join Date: Mar 2006 Location: Lot & Savoie Posts: 249	Re: ISC posts test data Quote: The retrofit valves for Standard models are being manufactured as we speak (the holder size is different) Hi Jakub, Thank you to inform us when it will be available. __________________ -------------------- Jacques NPSFQQA-EDS IT # 007 (remué non agité) Last edited by J. V. : 2nd April 2008 at 08:17.
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