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Discussion Starter · #1 ·
here are the first results of testing performed today

please note that these results are preliminary, and are beiing overchecked on monday again (counter check of calibration of the breathing machine, another run)

1 APOC using EAC

WOB at 75 RMV, tidal volume 3 liter, 40m depth, air, 4°C, vertical position, optimised lung volume 1.96 J/l

EAC 2080 grams

PPCO2 measured in the inhale hose (so better result then in mouthpiece)
1.6l/min CO2 STPD, 40 RMV, tidal volume 2 liters, 4°C, air, vertical position

5 mbar break-trough: 45 minutes
20 mbar break-trough: 78 minutes

2 APOC using sofnolime 797, 2004 gram in the same volume

WOB at 75 RMV, tidal volume 3 liter, 40m depth, air, 4°C, vertical position, optimised lung volume 2.39 J/l

PPCO2 measured in the inhale hose (so better result then in mouthpiece)
1.6l/min CO2 STPD, 40 RMV, tidal volume 2 liters, 4°C, air, vertical position

5 mbar break-trough: 52 minutes
20 mbar break-trough: 67 minutes


conclusion: under these test conditions, and to be verified, 5mbar break-trough (CE condition), granular sorb lasts longer
when looking at the 20 mbar break-trough, the EAC lasts longer

graphs of the tests are available
 

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Duvet Diver
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Paul,
It's probably a typo, but for the WOB tests the EAC test states tidal volume as 2l, the granular test states tidal volume as 3l.
Regards
Simon A
 

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Discussion Starter · #3 ·
Paul,
It's probably a typo, but for the WOB tests the EAC test states tidal volume as 2l, the granular test states tidal volume as 3l.
Regards
Simon A
no, no typo, look again :)
WOB is always at tidal 3 liters
CO2 endurance is always 2 liter
paul
 

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A VS Cash Cow
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those numbers are pretty low, regardless of EAC or granular. Less than an hour on a scrubber.
 

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Discussion Starter · #6 ·
those numbers are pretty low, regardless of EAC or granular. Less than an hour on a scrubber.
indeed! but to be fair: the conditions are hard: 1.6 L STPD, at 4°C..... nobody does this

if we have time w'll make a comparison at more 'normal' diving conditions, say 15°C and 1.2 l STPD
 

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A VS Cash Cow
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if we have time w'll make a comparison at more 'normal' diving conditions, say 15°C and 1.2 l STPD
and while your at it could you go through all the CCR units available and do this.....:)

I know its not realistic and manufacturers would never put this info out but i've always wanted to know how units work on a more realistic level
 

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here are the first results of testing performed today

please note that these results are preliminary, and are beiing overchecked on monday again (counter check of calibration of the breathing machine, another run)

1 APOC using EAC

WOB at 75 RMV, tidal volume 3 liter, 40m depth, air, 4°C, vertical position, optimised lung volume 1.96 J/l

EAC 2080 grams

PPCO2 measured in the inhale hose (so better result then in mouthpiece)
1.6l/min CO2 STPD, 40 RMV, tidal volume 2 liters, 4°C, air, vertical position

5 mbar break-trough: 45 minutes
20 mbar break-trough: 78 minutes

2 APOC using sofnolime 797, 2004 gram in the same volume

WOB at 75 RMV, tidal volume 3 liter, 40m depth, air, 4°C, vertical position, optimised lung volume 2.39 J/l

PPCO2 measured in the inhale hose (so better result then in mouthpiece)
1.6l/min CO2 STPD, 40 RMV, tidal volume 2 liters, 4°C, air, vertical position

5 mbar break-trough: 52 minutes
20 mbar break-trough: 67 minutes


conclusion: under these test conditions, and to be verified, 5mbar break-trough (CE condition), granular sorb lasts longer
when looking at the 20 mbar break-trough, the EAC lasts longer

graphs of the tests are available
Even your WOB results are so far off those produced by 5 other labs (one of which was a direct competitor another was a semi-competitor), that you need to have a decent auditor present.

On CO2, I am sorry but again you are disagreeing with numerous other labs, each of which have been doing CO2 endurance tests for longer than you have been diving rebreathers.

Please show the CO2 waveform in the mouth, or any other cal data. For example, if you don't have a set of scales (costing a few hundred Euro) to weigh the CO2, then you need to explain how you control the flow rate as the pressure increases or reduces.

Why don't you show the CO2 waveform in the mouth? That would allow anyone immediately to check you are injecting the correct amount of gas. Or measure the weight of the CO2 you inject: a very solid method of confirming your flow is right.

If you use a bubble method for measuring gas flow on the surface, what are you doing to correct it for depth? Flow through an orifice, or even an Mass Flow Controller, varies as the pressure differential changes.

I attach typical plots for 40 lpm RMV. These have been audited by SGS. Who witnessed the CO2 tests, and they have witnessed MANY companies CO2 tests so not a fly passes without notice.

Moreover, our plots do agree across 3 labs (5 labs checked WOB, 3 labs measured CO2 endurance and get figures very close to each other). The hump occurs at 100m depth, and our stated durations are on the basis of that hump exceeding limits. At 40m, it is not really an issue, as you see.


Alex
 

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Discussion Starter · #13 ·
Even your WOB results are so far off those produced by 5 other labs (one of which was a direct competitor another was a semi-competitor), that you need to have a decent auditor present.
show the 5 results of the labs!

On CO2, I am sorry but again you are disagreeing with numerous other labs, each of which have been doing CO2 endurance tests for longer than you have been diving rebreathers.

no, we are not that far away from your finding: I suppose you used 1.6 RT in stead of STPD, and then our results match

Please show the CO2 waveform in the mouth, or any other cal data. For example, if you don't have a set of scales (costing a few hundred Euro) to weigh the CO2,

again, bollocks, please show me the few hundred euro 7 digit accuracy scale as you already staded 3 times now

then you need to explain how you control the flow rate as the pressure increases or reduces.

again you show here you do not understand how correct mass flow monitoring works: the pressure is always constant on the mass flow meter
the setup is easy: CO2 tank, precision pressure reducer to 15 bar, mass flow meter, mass flow controll valve, outlet to vessel
you measure at the outlet, you set a mass flow, on the controller, and the display constantly shows you the IST


Why don't you show the CO2 waveform in the mouth? That would allow anyone immediately to check you are injecting the correct amount of gas. Or measure the weight of the CO2 you inject: a very solid method of confirming your flow is right.

give me the scale and the accuracy of the scale you are using!

If you use a bubble method for measuring gas flow on the surface, what are you doing to correct it for depth? Flow through an orifice, or even an Mass Flow Controller, varies as the pressure differential changes.

the bubble measuring is at the outlet, the mass flow meter does not see any pressure difference

althow not related to this, as there is no pressure change on the mass flow meter, as for CMF, please read my article so you will understand better

I attach typical plots for 40 lpm RMV. These have been audited by SGS. Who witnessed the CO2 tests, and they have witnessed MANY companies CO2 tests so not a fly passes without notice.

whatever YOU say..

Moreover, our plots do agree across 3 labs (5 labs checked WOB, 3 labs measured CO2 endurance and get figures very close to each other). The hump occurs at 100m depth, and our stated durations are on the basis of that hump exceeding limits. At 40m, it is not really an issue, as you see.

show the 5 different lab results

extra info: calibration of the sensor is even on the CO2 graph itself: zero gas (pure nitrogen) and 5000 PPM CO2 cal gas
where do I see the calibration checks on you graphs?
 

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"Three sheds"
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I'm struggling a little bit here. I am a little wary of Paul's tests, as I'm a bit of a scientist at heart and it is just one run and he (rightly and honourably) caveats them as says they will be counter-checked tomorrow.

On the other hand Alex claims to have multiple tests from other labs. But then Alex has posted so much crap in the past I'm not inclined to believe him.

I don't know what to think.

Part of the problem it seems there isn't a 'standard' CO2 test. IIRC the CE requires a test where the rebreather 'dives' to 40m, then ascends to 6m until breakthrough. Of course it's no surprise that a test to a constant 40m breaks through a lot quicker.

Paul - have you done tests on other rebreathers under exactly the same conditions (eg constant depth at 40m?). What were the durations for those? Although I'm particularly interested in the JJ, the Inspo is a good benchmark unit.

Janos
 

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no, we are not that far away from your finding: I suppose you used 1.6 RT in stead of STPD, and then our results match
You are mistaken, they don't.

The 1.6lpm was STPD, as you can tell immediately from the exhale waveform we publish, so your results do not match at all to any other lab. You said plots are available: I emailed you for them. Please send them.
Please show the CO2 waveform in the mouth, or any other cal data. For example, if you don't have a set of scales (costing a few hundred Euro) to weigh the CO2,

again, bollocks, please show me the few hundred euro 7 digit accuracy scale as you already staded 3 times now
I sent you a list of 4 scales that are readily available and cheap, that have an accuracy and resolution hundreds of times better than the change in CO2.

It read:"
Our scales were bought from a Russian lab, and we get a 12 point annual cal cert for it. It has an RS232 output.

Lots of balances are available that can do the molecular weight of gases in cylinders.

Professional grade:
LABREPCO - Scales and Balances does 34kg see http://www.labrepco.com/docs/CPA Brochure.pdf

60kg with 1gram linearity, and they do 100kg:
WIGGEN HAUSER - A World of High Tech Scientific Products

Cheaper but good enough:
Weighing Scale - CE ISO RoHS (WT1003L-100kg/1g) - China Weighing Scale,Electronic Balance,Scale in Weighing & Measuring Apparatus
(you need to get it calibrated locally, though it comes with a cert - a cal at a National Lab costs us £50).

The difference in weight of the CO2 is a few kg, so 1 or 10gram resolution is fine, and if had it calibrated then even a consumer scale such as 100kg Bench Scales Small | discountscales would do the job."

then you need to explain how you control the flow rate as the pressure increases or reduces.

again you show here you do not understand how correct mass flow monitoring works: the pressure is always constant on the mass flow meter
the setup is easy: CO2 tank, precision pressure reducer to 15 bar, mass flow meter, mass flow controll valve, outlet to vessel
you measure at the outlet, you set a mass flow, on the controller, and the display constantly shows you the IST
I am afraid if you look carefully at the spec of the mass flow controller, you will find it is valid only over a very small pressure range. Typically just 2 or 3 bar differentials, though they vary depending on the make of gauge.

Why don't you show the CO2 waveform in the mouth? That would allow anyone immediately to check you are injecting the correct amount of gas. Or measure the weight of the CO2 you inject: a very solid method of confirming your flow is right.

give me the scale and the accuracy of the scale you are using!
Paul, if you can't use Google to find a scale, then read your email with a list of low cost scales: even the cheapest of these measure within 10gram accuracy, and 1g accuracy in 100kg is a cheap scale. A cal and cert costs just £50.

If you use a bubble method for measuring gas flow on the surface, what are you doing to correct it for depth? Flow through an orifice, or even an Mass Flow Controller, varies as the pressure differential changes.

the bubble measuring is at the outlet, the mass flow meter does not see any pressure difference
Exactly. The flow meter does not have the pressure difference on it. We wrote CMF descriptions before you started diving rebreathers,

I attach typical plots for 40 lpm RMV. These have been audited by SGS. Who witnessed the CO2 tests, and they have witnessed MANY companies CO2 tests so not a fly passes without notice.

whatever YOU say..
, no not whatever we say. There is a CE cert published on this, and extensive results including the exact test set up and the key cal data. If I was to post on here that the Notified Body has audited and witnessed the CO2 testing when he has not, that would be a very serious matter indeed. You statements are intended to be poison, without any substance.

Moreover, our plots do agree across 3 labs (5 labs checked WOB, 3 labs measured CO2 endurance and get figures very close to each other). The hump occurs at 100m depth, and our stated durations are on the basis of that hump exceeding limits. At 40m, it is not really an issue, as you see.

show the 5 different lab results

extra info: calibration of the sensor is even on the CO2 graph itself: zero gas (pure nitrogen) and 5000 PPM CO2 cal gas
where do I see the calibration checks on you graphs?
The calibration data on the CO2 being injected is listed in the report on our web site. This comprises the cal traceability of the equipment, the breath by breath CO2 readings in the mouth during the test. There is a full report on the breathing machine cal, and the lissajous for the breathing machine accuracy are in the WOB report on our web site (along with the dates of the NEDU orifice checks), all of which has been audited by the Notified Body.

Alex
 

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no, we are not that far away from your finding: I suppose you used 1.6 RT in stead of STPD, and then our results match
You are mistaken, they don't.

The 1.6lpm in our data was STPD, as you can tell immediately from the exhale waveform we publish, so your results do not match at all to us or the two lab we used for CO2 tests, nor does your WOB match any of the 5 labs. We published our results including the cal (see the WOB report on the DL web site), and published the CO2 data with its cal. You said plots are available for your test: I emailed you for them. Please send them.
Please show the CO2 waveform in the mouth, or any other cal data. For example, if you don't have a set of scales (costing a few hundred Euro) to weigh the CO2,

again, bollocks, please show me the few hundred euro 7 digit accuracy scale as you already staded 3 times now
I sent you a list of 4 scales that are readily available and cheap, that have an accuracy and resolution hundreds of times better than the change in CO2.

It read:"
Our scales were bought from a Russian lab, and we get a 12 point annual cal cert for it. It has an RS232 output.

Lots of balances are available that can do the molecular weight of gases in cylinders.

Professional grade:
LABREPCO - Scales and Balances does 34kg see http://www.labrepco.com/docs/CPA Brochure.pdf

60kg with 1gram linearity, and they do 100kg:
WIGGEN HAUSER - A World of High Tech Scientific Products

Cheaper but good enough:
Weighing Scale - CE ISO RoHS (WT1003L-100kg/1g) - China Weighing Scale,Electronic Balance,Scale in Weighing & Measuring Apparatus
(you need to get it calibrated locally, though it comes with a cert - a cal at a National Lab costs us £50).

The difference in weight of the CO2 is a few kg, so 1 or 10gram resolution is fine, and if you have it calibrated then even a consumer scale such as 100kg Bench Scales Small | discountscales would do the job."

then you need to explain how you control the flow rate as the pressure increases or reduces.

again you show here you do not understand how correct mass flow monitoring works: the pressure is always constant on the mass flow meter
the setup is easy: CO2 tank, precision pressure reducer to 15 bar, mass flow meter, mass flow controll valve, outlet to vessel
you measure at the outlet, you set a mass flow, on the controller, and the display constantly shows you the IST
I am afraid if you look carefully at the spec of the mass flow controller, you will find it is valid only over a very small pressure range. Typically just 2 or 3 bar differentials, though they vary depending on the make of gauge.

Why don't you show the CO2 waveform in the mouth? That would allow anyone immediately to check you are injecting the correct amount of gas. Or measure the weight of the CO2 you inject: a very solid method of confirming your flow is right.

give me the scale and the accuracy of the scale you are using!
Paul, if you can't use Google to find a scale, then read your email with a list of low cost scales: even the cheapest of these measure within 10gram accuracy, and 1g accuracy in 100kg is a cheap scale. A cal and cert costs just £50.

You did not answer my question: where is the breath by breath measurement of the CO2 in the mouth. EN 14143:2003 and the prEN requires this to be done, because it sorts out the amateurs straight away, showing up their incorrect flow rates. Where is that data? You promised us the plots, where are they? if you have not got a set of scales, and you have not checked the CO2 in the mouth, you are relying on the performance of an MFC which you check under very different conditions than you are using for the test.

If you use a bubble method for measuring gas flow on the surface, what are you doing to correct it for depth? Flow through an orifice, or even an Mass Flow Controller, varies as the pressure differential changes.

the bubble measuring is at the outlet, the mass flow meter does not see any pressure difference
Exactly. The flow meter does not have the pressure difference on it. We wrote CMF descriptions before you started diving rebreathers,

I attach typical plots for 40 lpm RMV. These have been audited by SGS. Who witnessed the CO2 tests, and they have witnessed MANY companies CO2 tests so not a fly passes without notice.

whatever YOU say..
, no not whatever we say. There is a CE cert published on this, and extensive results including the exact test set up and the key cal data. If I was to post on here that the Notified Body has audited and witnessed the CO2 testing when he has not, that would be a very serious matter indeed. You statements are intended to be poison, without any substance.

Moreover, our plots do agree across 3 labs (5 labs checked WOB, 3 labs measured CO2 endurance and get figures very close to each other). The hump occurs at 100m depth, and our stated durations are on the basis of that hump exceeding limits. At 40m, it is not really an issue, as you see.

show the 5 different lab results

extra info: calibration of the sensor is even on the CO2 graph itself: zero gas (pure nitrogen) and 5000 PPM CO2 cal gas
where do I see the calibration checks on you graphs?
The calibration data on the CO2 being injected is listed in the report on our web site. This comprises the cal traceability of the equipment, the breath by breath CO2 readings in the mouth during the test. There is a full report on the breathing machine cal, and the lissajous for the breathing machine accuracy are in the WOB report on our web site (along with the dates of the NEDU orifice checks), all of which has been audited by the Notified Body.

Most labs don't post on web forum, and you know that. If you have any results that you believe contradict anything we have published, that would stand up, you would raise it with the Notified Body in an instant to get our CE cert taken down, but you don't.

Alex
 

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Discussion Starter · #17 · (Edited)
I'm struggling a little bit here. I am a little wary of Paul's tests, as I'm a bit of a scientist at heart and it is just one run and he (rightly and honourably) caveats them as says they will be counter-checked tomorrow.

On the other hand Alex claims to have multiple tests from other labs. But then Alex has posted so much crap in the past I'm not inclined to believe him.

I don't know what to think.

Part of the problem it seems there isn't a 'standard' CO2 test. IIRC the CE requires a test where the rebreather 'dives' to 40m, then ascends to 6m until breakthrough. Of course it's no surprise that a test to a constant 40m breaks through a lot quicker.

Paul - have you done tests on other rebreathers under exactly the same conditions (eg constant depth at 40m?). What were the durations for those? Although I'm particularly interested in the JJ, the Inspo is a good benchmark unit.

Janos
Janos, we always do tests according to the same protocol, we call this 'surface start to constant depth'
it is to reproduce what the real diver would do

machine is completely set up, exhaled gas 32°C, 100% humid,
we start breathing and injecting CO2 at surface, and then go diving immediately: the unit must be at 40m depth within 5 minutes from start injecting, and we stay at 40m till break-trough

this results in no CO2 data in the first minute, as only gas is sampled to the analyser when the vessel get's pressurised: you notice this from the graphs, CO2 goes from surface air (around 400PPM) to zero or base-level when coming from the rebreather

during the run we do at least one zero-check, and one 5000PPM check, so you see the cal gas data on the graph

ps: forgot to add: CE does NOT require going to 40m and then ascending to 6m till break-trough: that is in no way in the standard
 

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Discussion Starter · #18 ·
Alex, you produce to much text, so let's make it easy:

1 claim was EAC's do far longer then granular: we showed this was not true

2 you wrote: a few hundred euro's for a 10mg accuracy scale, I wrote: show me, and you can not: all you show is best 1 gram

3 we are not so far off: we wrote 45 minutes, you have a 52 minute in your data I believe

4 the mass flow meter works at 15 bar constant, no variation in our measurement

5 even not related to this: please give me the flow variation over an orifice with inlet pressure 15 bars, and outlet pressure change from 1 to 5 bars! (because you write that it changes, so please tell me how much!)

6 You statements are intended to be poison, without any substance.... I think you don't understand how often people here have that feeling..

7 tell me how you SET the CO2 injection when you start a test!
 

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You think I know nothing....and I do!!
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This is a pretty historic occasion we are witnessing here, we have two/three very clever individuals and manufacturers on a public forum activley attempting to discredit one anothers data and products.

As direct competitors and clearly very intelligent people has anyone really thought about the end game here?

Does anyone really think it will end well?

Like all pissing contests, it is going to end in tears.
 

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"Three sheds"
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Janos, we always do tests according to the same protocol, we call this 'surface start to constant depth'
it is to reproduce what the real diver would do
Thanks Paul.

Sorry - I wasn't very clear. I get that you're doing a 40m continuous depth. But the 'benchmark' in my head is that an Inspo scrubber lasts for three hours now clearly this isn't at 40m!

To help me put it in context, do you have the scrubber duration for other breathers at a constant depth of 40m?

Janos
 
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