How long will you let the scrubber sit
- Thread starter opheim
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gianaameri
gian @ gian.ameri.name
fftopic:
Time to split this CE stuff into a thread that can die like the last one did...
The issue is that JJ has published clear test results for WOB, while APD has not done so to the same extent as JJ, and NEDU has published result showing that the Inspiration as tested by NEDU is neither conformant to EN14143 nor Warkander.
I will add that no manufacturer has tested scrubber endurance for multiple dives over the same day or several days, although we hear QinetiQ has said something about this at RF3 (but no data or test results proffered).
Is this off-topic or can we continue?
matt
Well-Known Member
Yes, it's a great advantage. I also agree that blindly publishing the data isn't useful as it's confusing to more people than not. Perhaps a layman's comparison chart like the dishwasher one I posted a few posts back is a good idea after all
I had a quick look - perhaps you can help me - ATP versus BTPS.
Mindful of this comments:
and noting that the chart on the JJ is indeed in BTPS how do I find 40RMV (40ATP?) on that BTPS chart? (I only just encountered this, much more interesting that CE!).
Perhaps I should look for this number instead for the comparison:
That's the Wardanker test and we know that 75ATS is 82BTPS (perhaps not very relevant, just as 10% and call it 44??).
Matt.
matt
Well-Known Member
For me at least the WOB discussion is interesting and sufficiently On Topic, but Manufacturer bashing and CE isn't. So I won't comment on those. A mod will no decide for the wider-community.
Matt.
matt
Well-Known Member
gianaameri
gian @ gian.ameri.name
Yes, it's a great advantage. I also agree that blindly publishing the data isn't useful as it's confusing to more people than not. Perhaps a layman's comparison chart like the dishwasher one I posted a few posts back is a good idea after all
I had a quick look - perhaps you can help me - ATP versus BTPS.
Mindful of this comments:
and noting that the chart on the JJ is indeed in BTPS how do I find 40RMV (40ATP?) on that BTPS chart? (I only just encountered this, much more interesting that CE!).
Perhaps I should look for this number instead for the comparison:
That's the Wardanker test and we know that 75ATS is 82BTPS (perhaps not very relevant, just as 10% and call it 44??).
Matt.
Matt,
in layman terms, what is your point?
matt
Well-Known Member
I found what I'm looking for - a simple case of not knowing what's what!
JJ Rear Mounted CL:
22.6ATP (25.5BTPS) 40m Air, 0.54J/l.
74.3ATP (83.5BTPS) 100m 11/65, 1.71J/l.
Numbers looks pretty close to the ones Martin posted for the Inspiration (my suspicion over those peer-reviewed numbers continues!).
Matt.
JJ Rear Mounted CL:
22.6ATP (25.5BTPS) 40m Air, 0.54J/l.
74.3ATP (83.5BTPS) 100m 11/65, 1.71J/l.
Numbers looks pretty close to the ones Martin posted for the Inspiration (my suspicion over those peer-reviewed numbers continues!).
Matt.
gianaameri
gian @ gian.ameri.name
Matt,
no one is singling out any manufacturer and CE is an appropriate topic in the context of WOB and applicable standards (EN14143 vs. Warkander).
I think you resent that the APD Inspiration has been brought in the spotlight by the recently published NEDU report, but this does not amount to manufacturer bashing.
You cannot talk WOB without talking about WOB best science and disregard the best research by Warkander and NEDU on the subject, just because it does not suit you.
That is my honest personal view.
matt
Well-Known Member
Are you not. Go back an re-read what you put in your posts and stop bring it up for me to reply.
I'm not interested in you fascination with CE, I thought I had made it clear.
How wrong. I found the report interesting, I'm still unconvinced that it is right, but frankly who cares what I think.
Yes I can. I can give whatever opinion I like.
It makes no different to anyone what I do. Don't let it keep you up at night.
Good, I've replied for you. Now let's see if you can avoid replying back.
Matt.
gianaameri
gian @ gian.ameri.name
I accept I am critical of CE because it adopts an upper WOB limit which according to Warkander is unsafe. This I admit openly.
I deny being critical of any single manufacturer, maybe equally critical of some common manufacturer practices in relations to Certification, but categorically I am NOT singling out any manufacturer.
matt
Well-Known Member
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gianaameri
gian @ gian.ameri.name
According to EN14143:
"5.6.1.2 Work of breathing (WOB)
Work of breathing shall not exceed a value of:
WOB = 0,5+0,03*RMV [J l-1] related to an RMV from 10 l min-1 to 75 l min-1"
So, 0.5 + 0.03 * 75 = 2.75 j/l
Warkander sets the maximum limit to 2.0 j/l while EN14143 sets it to a more risky level of 2.75 j/l.
Just for clarity as I have no clue what Matt is trying to do with charts and numbers.
"5.6.1.2 Work of breathing (WOB)
Work of breathing shall not exceed a value of:
WOB = 0,5+0,03*RMV [J l-1] related to an RMV from 10 l min-1 to 75 l min-1"
So, 0.5 + 0.03 * 75 = 2.75 j/l
Warkander sets the maximum limit to 2.0 j/l while EN14143 sets it to a more risky level of 2.75 j/l.
Just for clarity as I have no clue what Matt is trying to do with charts and numbers.
matt
Well-Known Member
gianaameri
gian @ gian.ameri.name
Matt,
I am honestly interested in the subject and what you think you discovered, but cannot understand it.
How do you get to 62% and it is 62% of what and what is the meaning of it?
matt
Well-Known Member
LOL.
Matt.
96% CIS Lunar has a 2.66 j/l WOB at 300 feet and 75 RMV
66% AP Diving Inspiration has a 1.84 j/l WOB at 100m and 75 RMV
67% MK16 has a 1.85 j/l at 300 feet and 75 RMV
75% MK16 Mod 2 has a 2.08 j/l at 300 feet and 75 RMV
63% Stealth MOD has a 1.71 j/l at 300 feet and 75 RMV
66% Viper E Stealth MOD has a 1.82 j/l at 300 feet and 75 RMV
62% JJ has a 1.71J/l WOB at 100m and 75 RMV (11/65)
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matt
Well-Known Member
Martin proposed that the measurement be given not as J/l but as a percentage of target.
I admit that I'm a bit confused that the chart from JJ when (crudely extrapolated) shows the limit close to 3.0 when the standard (as you quote) say 2.75, but I went with 2.75.
So 1.71/2.75 = 62%.
I went with Martin's retested results in the modified table (originally made by you).
It's also possible the gas was different between the JJ and others, but I didn't check (yet).
Results look consistent, and I improved my understanding a little.
Matt.
gianaameri
gian @ gian.ameri.name
So, as percentage of target the NEDU results show:
CIS Lunar has a 2.66 j/l WOB at 300 feet and 75 RMV = 96% of EN14143, but in excess of Warkander safe limit.
AP Diving Inspiration has a 2.98 j/l WOB at 300 feet and 75 RMV = in excess of both EN14143 and Warkander limit (too risky)
MK16 has a 1.85 j/l at 300 feet and 75 RMV = 0.67% of EN14143 and 92.5% of Warkander limit
MK16 Mod 2 has a 2.08 j/l at 300 feet and 75 RMV = in excess of both EN14143 and Warkander limit (too risky)
Stealth MOD has a 1.71 j/l at 300 feet and 75 RMV = 62.18% of EN14143 and 0.85% of Warkander limit
Viper E Stealth MOD has a 1.82 j/l at 300 feet and 75 RMV = 0.66% of EN14143 and 0.91% of Warkander limit
where EN14143 limit is 2.75 j/l and Warkander limit is 2.0 j/l
matt
Well-Known Member
Against a limit of 2.0:
133% CIS Lunar has a 2.66 j/l WOB at 300 feet and 75 RMV
92% AP Diving Inspiration has a 1.84 j/l WOB at 100m and 75 RMV
93% MK16 has a 1.85 j/l at 300 feet and 75 RMV
104% MK16 Mod 2 has a 2.08 j/l at 300 feet and 75 RMV
86% Stealth MOD has a 1.71 j/l at 300 feet and 75 RMV
91% Viper E Stealth MOD has a 1.82 j/l at 300 feet and 75 RMV
86% JJ has a 1.71J/l WOB at 100m and 75 RMV (11/65)
Matt.
133% CIS Lunar has a 2.66 j/l WOB at 300 feet and 75 RMV
92% AP Diving Inspiration has a 1.84 j/l WOB at 100m and 75 RMV
93% MK16 has a 1.85 j/l at 300 feet and 75 RMV
104% MK16 Mod 2 has a 2.08 j/l at 300 feet and 75 RMV
86% Stealth MOD has a 1.71 j/l at 300 feet and 75 RMV
91% Viper E Stealth MOD has a 1.82 j/l at 300 feet and 75 RMV
86% JJ has a 1.71J/l WOB at 100m and 75 RMV (11/65)
Matt.
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gianaameri
gian @ gian.ameri.name
Not according to the NEDU test, but if it makes you happy :thumbsup:
Martin Parker
New Member
At 75 RMV the Inspiration is 1.84 j/l at 100.3m or 329ft
At 89.9m (295ft) it's 1.75 j/l
By interpolating, at 300 ft = 1.76 to 1.77 j/l
(All tests done at 4.3 C, all figures ATP, no BTPS adjustment. )
To put it into perspective, the limit is 2.75 j/l but with BTPS conversion. To find the 75 lpm BTPS level I'd have to test at 62.5 lpm and then convert both to BTPS and interpolate between the two. 75 RMV (ATP) was 82 (BTPS) from memory at 4.3C and 100.3m.
In 2002 when the NEDU test was done, the WOB limit was the one for OC regulators, 3.0 j/l. They tested one over this and one under, giving their average of 2.98. having seen much lower figures at QinetiQ I know there's an error in their testing.
All test houses are capable of making mistakes and I have challenged NEDU on their figures. We'll see whether they can be bothered to re-test
Since 2004, the Inspirations have been inside the EN14143:2003 limits and this has been proven by extra audits and external testing.
But, as I pointed out in my first post... A p*ssing contest on WOB is a waste of time, you need to take into account elastance and hydrostatic imbalance as well.
Humans are really good at feeling hydrostatic imbalance and often confuse that with work of breathing, elastance takes them a little longer to pick up but the pain arrives eventually, WOB or resistive flow historically isn't so easy to feel...look at the regulators produced in the 70s and 80s...there were probably only a couple of models that would meet today's EN250, (3 j/l limit at 50m (air) at 62.5 RMV.)
It's taken years to get agreement on how to even measure elastance and hydrostatic imbalance between both sides of the Atlantic and I'm not convinced the Hydrostatic imbalance test method is where it needs to be yet.
Dan Warkander's proposal is to add all three together, by adding the % of max. for each value, how valid that is I don't know but it would certainly give divers a better comparison tool. All figures would have to be gleaned in all positions which as Dave said is less onerous when you have your own machine and is something for the future but to have all those tests done and externally verified would be mega expensive and I can't see that getting through the standards committee without a lot of proof as to it's worth.
While I am writing about the European Standards Committee, Gian's comments about the makeup of the committee is wrong. As far as I am aware, explanations have been given to him as to why his claims for defective standards have been rejected. He claims commercial interest drove those decisions but my understanding is that the make up of the committee was provided which would make it clear that the make up is a balanced group comprised of physiologists, test houses, user group representatives as well as manufacturers and training organisations.
My understanding is that collectively and unanimously they rejected his claims.