For the alternative view, see Simons comment about the logic of decision making by customers, being better if the do not know the WOB of what they are buying.
I don't think you score any points or change any minds by being ridiculous.
Simon, Please advise:
1) How many rebreather manufacturers admit to selling a "complex life support device";
2) Which rebreather manufacturers only sell a diver a rebreather AFTER training has been conducted on the unit?
I'm not sure what the point of the complex life support device question is.
Most (and possibly all) manufacturers will sell a rebreather for the purposes of training. No problem with that. They are requiring that training has either been taken, or is in place, before selling the unit. You, on the other hand, will sell a rebreather to anyone irrespective of whether they have received training, and then you criticise other manufacturers for not reporting as much WOB data as you do.
and Simon, the reason that the criteria exist in the standards is that they occur in real world diving. What does Guessing the middle of the envelope or bell curve prove?
I don't think we disagree on this Brad. I am not suggesting the standards are wrong or that they should change. I was merely observing that the extreme conditions defined by the standards occur rarely in real life. I agree they do occur.
Only Simon, if one relies on internet posts and one fails to consider evidence to the contrary.
That is nonsense Brad. Are you suggesting that Alex was intentionally providing an incorrect description of the original method? People can read the thread for themselves. It is obvious that he was describing a method for direct measurement of end of exhale CO2 at the end of the exhale hose, and it was interpreted exactly that way by other experts reading that thread. And it was typical of Alex that even when those medical professionals who use end tidal CO2 monitoring equipment every day of their working lives told him he was using a flawed technique, he continued to insist he was right. The purpose of our paper was to publish the problem in an authoritative resource so that people would not have to rely on an internet debate.
and Simon I believe as you are well aware, the critical point you gloss over is that you failed to be definitive either way. IIRC at the time Alex pointed out to you that with the heath robinson affair you used for a loop, DL with an entire engineering team behind them, would have failed to measure end-tidal CO2 at the end of the loop either, certainly no may about it.
More obfuscation. There was no "critical point" and nothing was ever "glossed over". We tested exactly the method of measuring end tidal CO2 Alex described in his posts, and desmonstrated exactly the vulnerability to inaccuracy that we predicted. Any comments he made about the result being expected were retrospective and only emerged after he realised his mistake. That, of course, is when you changed the method you were employing. That paper was peer reviewed by reviewers from Qinetic in the UK and the Environmental Physiology Laboratory at Duke in the USA. They did not see anything wrong with our methods or conclusions.
Whilst at the same time DL were using the iCCR Monitor to verify a Mass Specs readings of CO2 at 100m and identified an unchallenged flaw with in-service DSV and BOV flapper valves.
http://www.deeplife.co.uk/or_files/Fault_Study_CO2_Bypass_110314.pdf
A completely unrelated matter.
Simon, Could you please cite the references for this.
MITCHELL SJ, BOVE AA. Medical screening of recreational divers for cardiovascular disease: Consensus discussion at the Divers Alert Network Fatality Workshop. Undersea Hyper Med 38, 289-296, 2011
Because with all due respect, I know what you are quoting (on this specific topic before too many fans get their knickers in a knot) is crap. I not only know both sides, I know all three sides (in at least some detail for each): whereas you refuse to accept you have only had limited access to one. Even that evidence, you are looking at, with blinkers on.
I ask my question again. How would you know what I know or don't know.... because you have not answered it above.
Simon, the only slight hiccup I see with this argument you keep trotting out as if it means anything, is that nothing has actually changed with regards how the iCCR measures end-tidal CO2.
A classic Horn word play (as pointed out many times before). You have not changed the sensor that measures the CO2 at the end of the exhale hose - agreed. What you have done is to introduce an algorithm to compensate for the dilutional effects of anatomic and equipment dead space that become more important at low tidal volumes. You know, the dead space that Alex spent a lot of time arguing didn't matter (see my previous post
http://www.ccrexplorers.com/showthread.php?t=18488&p=179101&viewfull=1#post179101). Brad, attempts to obfuscate this when it is all there in his own words in the public domain really don't do you any favours.
Agreed, because I am fully in support of proper training. It would however be even better if that proper training mandated the use of BOVs and retaining straps!
This is an entirely different discussion, but I don't necessarily disagree with you on that.
I get it. So the logic of someone elses decision, tells why your kept in the dark and why you do not know the WOB of your own OCB yet at the same time allowing you to cite the recommended WOB that your UBA should meet; to be safe to dive.
It is not a matter of "safe" vs "unsafe". I don't disagree that a low WOB, all other factors being equal, is desirable and contributes to safety. What I know is that the equipment I use will allow me to cope with the majority of bailout situations I am likely to encounter. There is a very small proportion of situations that I would cope better with if I had a lower WOB device. My risk vs benefit evaluation of that is that it is acceptable to me. Indeed, there is currently no plausible alternative in the rebreather configuration I like to dive. My advice to you is that instead of (hypocritically) seeing this as a point mof attack on other manufactures you see it as a potential point of difference if you can bring such a plausible alternative to market which at this point you have not.
Simon M
