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Thread: Prebreathe study

  1. #1
    New Member Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell's Avatar
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    Prebreathe study

    Hello,


    In the course of discussion about the comparative sorb study a few people have asked me about the availability of the prebreathe study.


    You can access it here:


    https://dl.dropboxusercontent.com/u/...absorption.pdf


    Simon M

  2. #2
    RBW Member decostanza is an unknown quantity at this point decostanza's Avatar
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    rEvoIII Ti

    Re: Prebreathe study

    Fascinating study and thank you for making it available...

  3. #3
    Chett Lehrer Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L has much to be proud of Chett.L's Avatar
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    rEvo FT / Hollis P-2/ rEvo lll

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    Re: Prebreathe study

    Thanks for your continued support.

    Best regards,
    Chett. L

  4. #4

    Re: Prebreathe study

    Simon. After reading the study about pre breath, I'm thinking if a study about the quality of a scrubber filling isn't a good point to investigate. Maybe, know if divers are capable of preparing the scrubber correctly can be a better way to avoid hipercapnia than rely in pre breath. What do you think?

  5. #5
    New Member Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell has a reputation beyond repute Simon Mitchell's Avatar
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    Re: Prebreathe study

    Quote Originally Posted by luciobio  View Original Post
    Simon. After reading the study about pre breath, I'm thinking if a study about the quality of a scrubber filling isn't a good point to investigate. Maybe, know if divers are capable of preparing the scrubber correctly can be a better way to avoid hipercapnia than rely in pre breath. What do you think?
    Hello,

    In principle you are absolutely correct. One of the conclusions of the study was that there should be strong emphasis on preventing the problem of faulty CO2 scrubbing at the beginning of a dive rather than trying to detect it with an unreliable strategy. Prevention includes proper canister packing and correct canister installation. Aspects of this might be amenable to being studied, but the message is clear even in the absence of a study. We need to try to get it right because in the absence of an inhaled CO2 detector there is no way of telling whether thhe scrubber is working properly.

    Simon M

  6. #6
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
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    Re: Prebreathe study

    Quote Originally Posted by Simon Mitchell  View Original Post
    Prevention includes proper canister packing and correct canister installation.
    Prevention should also include design of scrubber that doesn't easily permit miss assembly and promotes reliable consistent error free packing. unfortunately fault tolerance is not even something that comes up on any CE test for rbs.....

    prevention is always better than cure, but the best prevention is to `design away the problem` in the first place - by responsible design or possibly sticking to using micropore cannisters

    some scrubber designs are more prone to packing/assembly/settling/channelling problems than others.

    One example of such a case is the ridiculous non captive o-ring and spacer in the classic inspo. classic example of poorly though out fault intolerant design. When designing any life critical device the designer should be continuously asking himself, could this part be easily miss assembled? could it be missed all together from the assembly? could it easily be badly filled/packed?

    I suggest that putting the onus on the user to prebreath to check he hasnt made an assembly or packing error (as well as to start the reaction) although advisable, certainly for the latter, should not be accepted as a reason to allow for the mnf to get away with a weak fault intolerant scrubber design that would too easily allow such assembly or packing error in the first place.

    I recall issues with co2 bypass on the classic inspo due to that awful (lazy/poorly thought out) o-ring and spacer design - at that time the masses happily accepting a good pre breath as an acceptable `cure` to highlight any miss assembly, instead of asking the question `why does this design permit so easily an assembly error`. few if anyone at that time had the audacity to suggest that perhaps the design was partly negligent. It always amazes me how the community is so eager and ready to add diver checks to take the burden of responsibility over the manufacturer to account for unnecessary risk that the mnf could through responsible and decent design have design out
    Last edited by Drmike; 1st August 2016 at 02:33.

  7. #7
    RBW Member rjack will become famous soon enough rjack will become famous soon enough rjack will become famous soon enough rjack's Avatar
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    Meg

    Re: Prebreathe study

    For once I without reservation agree with drmike. Designing equipment so that faults can't happen in the first place is the ideal (industrial) design. Or if an error does happen its patently obvious (like the parts don't fit or it instantly and unequivocally fails a positive/negative test)

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