gianaameri
gian @ gian.ameri.name
We have had remarkably different experiences, that is all.
Are you saying your unit always worked flawlessly and never required any factory "upgrades?"
How long will you let the scrubber sit
- Thread starter opheim
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We have had remarkably different experiences, that is all.
Are you saying your unit always worked flawlessly and never required any factory "upgrades?"
Martin Parker
New Member
Scrubber use
I won't enter into dialogue with you but you write as if you know what you are talking about and the lay person could be misled:
Having done a shit load of testing at several test houses I can tell you those figures on the Inspiration are wrong. When a test house gets a result, they don’t know whether it’s spurious or not unless they test that product a lot - but that one stands out a mile, to me.
We tend to stick to Trimix testing at 100m, so I had that test repeated yesterday using Heliox.
At 75 RMV (ATP), 1.3 bar PO2, at 100.3m the WOB on an Inspiration, Vertical, 4.3C, is 1.84 j/l , at 89.9m it’s 1.75 j/l.
(ATP refers to actual temperature and pressure, i.e. there is no conversion for BTPS -Body temperature pressure saturated - the EN14143 WOB limits are BTPS – the BTPS breathing rate in this test was over 82 RMV)
So why did they get higher values? I suspect they didn’t have just Heliox in the loop. I contacted the author of that report yesterday and he advised that the Inspirations were tested prior to 2002 and couldn’t comment on the technique used for testing as he wasn’t at NEDU then. I have asked them to consider a re-test.
There comes a point when common sense says - throw it away. However, our temp-stick will give appropriate warnings in this instance.
We know diving deep and working hard on a part used scrubber is a recipe for disaster.
I won't enter into dialogue with you but you write as if you know what you are talking about and the lay person could be misled:
If you use the formula in the std, you can work out the max. allowed at the various breathing rates and by applying the % I quoted you can work out what our WOB is ... It's not confusing, I thought it might be an idea to start quoting WOB as a % of the max. allowed, I thought it would be more meaningful in determining the effect of a scrubber duration test. I only had the numbers at hand for 40 RMV and there wasn’t much point in quoting the actual joules/litre without putting it into context.
it doesn't confirm your hypothesis at all. You don’t know whether there was any clumping or not.
Maybe it does, maybe it doesn't.
When you have done some testing please let us know your results. This suspicion of yours isn’t supported by our testing.
It was revealed at RF3 that Qinetiq have done such testing and haven't found any cause for concern.
The topic is, how does the WOB change during scrubber usage. I have pulled some of the data we have out to help the topic along...the scrubber runs are done at 40 RMV .....and then Matt asked me if I can provide WOB data for lower RMV.. which I provided. The EN14143 requires WOB testing at all breathing rates.
You’re aware that your claim for defective standard on these grounds was rejected.
Having done a shit load of testing at several test houses I can tell you those figures on the Inspiration are wrong. When a test house gets a result, they don’t know whether it’s spurious or not unless they test that product a lot - but that one stands out a mile, to me.
We tend to stick to Trimix testing at 100m, so I had that test repeated yesterday using Heliox.
At 75 RMV (ATP), 1.3 bar PO2, at 100.3m the WOB on an Inspiration, Vertical, 4.3C, is 1.84 j/l , at 89.9m it’s 1.75 j/l.
(ATP refers to actual temperature and pressure, i.e. there is no conversion for BTPS -Body temperature pressure saturated - the EN14143 WOB limits are BTPS – the BTPS breathing rate in this test was over 82 RMV)
So why did they get higher values? I suspect they didn’t have just Heliox in the loop. I contacted the author of that report yesterday and he advised that the Inspirations were tested prior to 2002 and couldn’t comment on the technique used for testing as he wasn’t at NEDU then. I have asked them to consider a re-test.
The WOB does increase but as I showed you, by not very much and the available evidence is suggesting this isn’t a problem.
You haven’t put any evidence forward. In this last sentence you have added “extended storage” – just how many variables do you want to add to this test?
There comes a point when common sense says - throw it away. However, our temp-stick will give appropriate warnings in this instance.
We know diving deep and working hard on a part used scrubber is a recipe for disaster.
gianaameri
gian @ gian.ameri.name
Gee... thank-you for all your expert contribution on the subject.
It is not true that I "write as I know what I am talking about."
I write about what I do know and quote the reference where I have sourced the knowledge from.
What I do not now, I say I do not know, and hope for more research on the subject.
I have made two Claims of Defective Standard in respect of EN14143:2003.
The "experts" who make the decision have rejected both. Regretfully, they have not provided a reason for the rejection. I suspect the reason is commercial interest , that is they place commercial interest ahead of safety.
As you are aware, the "experts" are largely manufacturers and certification agencies and there is no consumer representation (i.e. a "CE" styled Politburo, in my opinion).
If and when the "experts" provide a reason for their decision (i.e. a "reasoned response" as required by the terms of "openness and transparency" which the experts have agreed to operate under with the European Commission) not to lower the WOB maximum limit to a safer level based on the best science, I then reserve to change my personal belief in respect of the motives for the rejection.
The above would merit a separate thread and discussion, but since you brought the issue up, it required my reasoned response.
The best science (Warkander) does believe that the 2.75 j/l is way too high and it should be at most 2.0 j/l - but maybe Dr. Simon Mitchell can contribute his expert opinion on the subject (I would go with what Warkander and Mitchell say, rather than what manufacturers say).
In any event, for the layman the fact is that the higher the WOB in a rebreather, the more risky it is, and the lower the WOB, the better.
I look forward to see in due course revised results from NEDU, if as you suggest, NEDU got it wrong, and the report on QinetiQ findings.
matt
Well-Known Member
I said I didn't miss any dives. I think it's a pretty simple statement, not much interpretation to be had. I've never bailed-out either.
Some people look for problems, some go diving. I'm the latter. I don't have the exact hours in my pocket, but it's about 750.
Matt.
matt
Well-Known Member
Yes, I'd like to thank Martin too - that post is by far the most informative here. Much better to have some evidence from a test than a glass full of wet Sodalime on your mantle piece.
As far as I can see the Warkander Technical Report is self-published non-peer reviewed PDF?
Matt.
gianaameri
gian @ gian.ameri.name
Warkander research is scientific, published, and peer reviewed - the definitive scientific research in the field of WOB.
No peer has denied or refuted his findings, except for the CE Politburo - who is unable to substantiate the reasons for such unreasonable and unsafe position on the subject of WOB limits in CE land (a rapidly disintegrating sad version of the far better, proven, and sustainable US model).
If you cannot Google the Warkander scientific piece (it is on the net somewhere), Skype me or email me and will get you a copy.
My contacts are to the left of my posts, next to my picture(center) with the late Jordi Mateo (left) and Cedric Verdier (right).
matt
Well-Known Member
Good, which Journal (or other) did it appear in?
I already found it. BTW, I'm not saying it's wrong or anything, I'm just trying to figure out how it was elevated to the "definitive scientific research in the field" status.
Matt.
gianaameri
gian @ gian.ameri.name
Well, it is "what many view as the definitive reference on this subject."
The "many" includes renowned experts in the field, which excludes the "CE" Politburo (i.e. manufacturers and certification agencies insofar they have chosen to ignore it... if a rebreather is outside the upper limit proposed by Warkander and measured by NEDU, I would expect a manufacturer to improve on its WOB, and not ignore the best science, hence my "feelings" towards the "CE" Politburo).
Hopefully Dr. Mitchell will comment in this thread on the subject and the specifics of:
Physiologically and subjectively acceptable breathing resistance in divers' breathing gear, D. E. WARKANDER, W. T. NORFLEET, G. K. NAGASAWA, and C. E. G. LUNDGREN, Underwater Biomedical Research, Vol 19, No 6, 1992.
...and you will post a link to what you found for everybody to read!
matt
Well-Known Member
That's a different one, no?
The one you referenced before (with WOB numbers) is http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA550047 (which I already posted (with extract)).
Which journal did this one appear in: Work of Breathing Limits for Heliox Breathing, Warkander, D, November 2010.
Matt.
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gianaameri
gian @ gian.ameri.name
I referenced two different studies in my prior post, one by Warkander, and the other by NEDU.
Each stand on their own merit.
I think it is puerile and disingenious to attack the validity of these studies.
What Steve Jobs would do (since you like Apple and compare it with APD), he would get a 2002 Inspo and a 2012 Inspo (as they may be different one from the other) and tell his engineers to test each at 75 l/m at 300 feet on a gas with an "END of 24m" (pg. 7 of APD User Manual), and publish the results (or just shut up and fire a few people and come up with a new and improved model say "Inspiration 2").
On your next post you are going to ask "which post." To save me time, I put it now below:
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matt
Well-Known Member
Rather than attacking me, if you don't know just say.
You may have missed it, he's dead.
I think we can leave it there, Gian. If you figure out the answer then post it up.
Matt.
gianaameri
gian @ gian.ameri.name
I can confirm I don't know what I don't know, and this has always been the case, and will always be.
Now, Matt - don't take it personal if NEDU and Warkander see it differently from you.
You still never missed a single dive in 10 years on your rebreather and you are and should be very happy and proud about it and it is "CE."
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There seems to be a bit of CE bashing here and believe me I am not a fan of CE
but at the moment its the best we have.
. At least all rebreathers sold in Europe have to be tested and to a standard that is more or less common (note I said more or less) and some testing is better than none right!?
well its a start and better than an individual manufacturer making it up as he goes along
but at the moment its the best we have.
. At least all rebreathers sold in Europe have to be tested and to a standard that is more or less common (note I said more or less) and some testing is better than none right!?
well its a start and better than an individual manufacturer making it up as he goes along
matt
Well-Known Member
I'm trying not to get drawn in to CE bashing, but I do agree with what you said. Do you have those figures (perhaps expressed like Martin did) for the JJ?
Cheers
Matt.
before we put the JJ for CE we did some testing at quentiq to make sure we wernt barking up the wrong tree. all of that test data is here www.jj-ccr.com its in the downloads section
matt
Well-Known Member
Ta. I shall try looking for this out then when I have a few hours spare:
Inspiration said:
Matt.
gianaameri
gian @ gian.ameri.name
Currently, CE manufacturers are making up the standard as they go along.
This is a fact which I can substantiate in detail.
I do not mind that so much, provided there is disclosure as to such fact and a clear explanation of the implications for the user (i.e. my product is tested to standard xyz but it does not meet clause abc and this is what it means to you... or I made up my own standard and here it is so that you actually know what it entails and let me explain you why I did that and what it means to you...).
What I do mind is when I buy a product and I am led to believe it actually meets a particular standard, when it does not.
Equally, what I do not like is when I am led to believe as a consumer, when I buy a product, that it is more "dependable" than what it is.
So, any testing is better than no testing, but then the Certificate which is issued has to be complete and truthful and with no material non-disclosures.
What is the point of any testing if then the results are undisclosed (or the manufacturer can legally cherry-pick the results and disclose only the good findings and none of the bad findings)?
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well Gian I do sort of agree with you and its why I am not a fan of CE but like I said its better than nothing.
The question of publishing the results of ce testing came up at RBF3 and when the speaker gave an example of a figure (1.9 joules per litre, exp) there were not very many people in the room who actually understood what that meant!!
The question of publishing the results of ce testing came up at RBF3 and when the speaker gave an example of a figure (1.9 joules per litre, exp) there were not very many people in the room who actually understood what that meant!!
gianaameri
gian @ gian.ameri.name
Disclosure of conformances and non-conformances has to be made in a manner which is comprehensible to the intended recipient.
So, if you sell to QinetiQ... well you can just maybe quote j/l .
If you sell to Mom and Pop (i.e. people who are not experts in the field like I was when I bought my first rebreather and to a large extent still am...), then you quote the same number and provide a simple explanation (preferably a honest and non-deceptive one).
However, as a minimum, in all cases, when a Certificate is issued by a Professional, it has to be truthful and with no material non-disclosures.
If we compromise on that, then we are left with nothing.
I think its fair to note that Martin has the privilege of owning his own ansti testing machine, (as does Paul Raymakers) he is able to produce much more test data without incurring the huge costs of somebody who has to rent space at a test house. but of course that is his advantage and well deserved I might add
Personally if I had unlimited access to a machine there are many many tests I would like to do to further rebreather knowledge