Sentinel LSS - Trip Report

Drmike · 28th March 2008, 10:37

Quote: (Originally Posted by paulraymaekers)

Hello Matt, if you can breath 10 minutes from a unit with NO scrubber inside, withouth any signs..

paul

he breathes through his ears - thats why the girls love him

Drmike · 28th March 2008, 10:38

Quote: (Originally Posted by JonnyB)

That is true, but i do not believe someone would build in that as a functionality in their software.
Much better if they have one time for pre breading.

/Jonny

be easy to do seeing as the temp is known

Drmike · 28th March 2008, 10:42

Quote: (Originally Posted by paulraymaekers)

Ben, I think the concept of pre-breathing has nearly nothing to do with activating your scrubber (except for temp around freezing temp), but more as a general test for your functioning rebreather: does it work or not!
meaning, cells, verifiing befhaviour of cells, is the scrubber working or do you feel weard when breathing (did you pack the scrubber correct, or at all) etc etc etc

paul

yes but Ive just done a pre dive tests that verified all those things work. so the only thing it could be testing is scrubber breakthrough...and i strongly suspect anything less than a reasonably big bypas wouldnt show up pre breathing sat on a bench....but if someone proves me wrong Im happy to change my opinion. I dont recall ever hearing about anyone finding a problem with scrubber during pre breathe and I do recall people whos unit passed pre breaths then they had breakthrough on descent....

paulraymaekers · 28th March 2008, 12:44

Quote: (Originally Posted by Drmike)

yes but Ive just done a pre dive tests that verified all those things work. so the only thing it could be testing is scrubber breakthrough...and i strongly suspect anything less than a reasonably big bypas wouldnt show up pre breathing sat on a bench....but if someone proves me wrong Im happy to change my opinion. I dont recall ever hearing about anyone finding a problem with scrubber during pre breathe and I do recall people whos unit passed pre breaths then they had breakthrough on descent....

I agree fully that there is no need to do again a pre-breath when you did it an hour ago, and you did not change anything on your unit

paul

JonnyB · 28th March 2008, 14:08

Quote: (Originally Posted by Drmike)

be easy to do seeing as the temp is known

Then you introduce another failpoint.
you would need some other kind of sensor (read termometer) that can tell you accurate temperature and you would need to build logic into the unit that uses this.

I have seen these temperatures to vary a lot from one second to the other.
And I would not want any type of pre dive procedure to be evaluated on the fly. What's next, people diving in the arctis putting their handset in hot water just so they dont have to do the 5 minutes of pre breath?
People are stupid and they will do stupid things.
Plan your dive and time. And dive accordingly.

just my $0.02
Jonny

tecdivertraining · 28th March 2008, 23:17

Quote: (Originally Posted by paulraymaekers)

Hello Matt, if you can breath 10 minutes from a unit with NO scrubber inside, withouth any signs..

paul

Hi paul

on all Mix courses I have students remove their scrubbers and breath from their units obviously with the O2 on and wearing a mask I have yet to have one detect CO2 before 5 mins. try it and let me know how you go.

KevDD · 29th March 2008, 02:04

Quote: (Originally Posted by tecdivertraining)

Hi paul

on all Mix courses I have students remove their scrubbers and breath from their units obviously with the O2 on and wearing a mask I have yet to have one detect CO2 before 5 mins. try it and let me know how you go.

I did the same experiment and it took at least 4-5 mins before co2 build up became evident. This may however be accelerated by depth?

The point does still remain that the prebreath may not show anything even thought co2 is breaking through (depends how long you pre breathe it for ofcourse).

Mikel-Deko · 29th March 2008, 07:16

Maybe instead O2 if you breathe say EAN30 without the scrubber, you will detectec the CO2 earlier.
Just an idea...
Best
Mikel

Drmike · 29th March 2008, 10:02

Quote: (Originally Posted by tecdivertraining)

Hi paul

on all Mix courses I have students remove their scrubbers and breath from their units obviously with the O2 on and wearing a mask I have yet to have one detect CO2 before 5 mins. try it and let me know how you go.

thanks buddy, so its all tosh then...damn that 5min pre breathe is really gonna buy me now

Drmike · 29th March 2008, 10:05

Quote: (Originally Posted by JonnyB)

Then you introduce another failpoint.
you would need some other kind of sensor (read termometer) that can tell you accurate temperature and you would need to build logic into the unit that uses this.

I have seen these temperatures to vary a lot from one second to the other.
And I would not want any type of pre dive procedure to be evaluated on the fly. What's next, people diving in the arctis putting their handset in hot water just so they dont have to do the 5 minutes of pre breath?
People are stupid and they will do stupid things.
Plan your dive and time. And dive accordingly.

just my $0.02
Jonny

scrubber temp is known - as in thermister is already built in to each unit and loop gas temp is already measured.

Piece of cake programming wise to just reduce the pre breasthe period to suit the loop temp, afterall the only way to cheat (increase) the loop temp is to pre breathe

28th March 2008, 10:37	#41 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,128	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by paulraymaekers) Hello Matt, if you can breath 10 minutes from a unit with NO scrubber inside, withouth any signs.. paul he breathes through his ears - thats why the girls love him __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you
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28th March 2008, 10:38	#42 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,128	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by JonnyB) That is true, but i do not believe someone would build in that as a functionality in their software. Much better if they have one time for pre breading. /Jonny be easy to do seeing as the temp is known __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you
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28th March 2008, 10:42	#43 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,128	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by paulraymaekers) Ben, I think the concept of pre-breathing has nearly nothing to do with activating your scrubber (except for temp around freezing temp), but more as a general test for your functioning rebreather: does it work or not! meaning, cells, verifiing befhaviour of cells, is the scrubber working or do you feel weard when breathing (did you pack the scrubber correct, or at all) etc etc etc paul yes but Ive just done a pre dive tests that verified all those things work. so the only thing it could be testing is scrubber breakthrough...and i strongly suspect anything less than a reasonably big bypas wouldnt show up pre breathing sat on a bench....but if someone proves me wrong Im happy to change my opinion. I dont recall ever hearing about anyone finding a problem with scrubber during pre breathe and I do recall people whos unit passed pre breaths then they had breakthrough on descent.... __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you
(Offline)

28th March 2008, 12:44	#44 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,362	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by Drmike) yes but Ive just done a pre dive tests that verified all those things work. so the only thing it could be testing is scrubber breakthrough...and i strongly suspect anything less than a reasonably big bypas wouldnt show up pre breathing sat on a bench....but if someone proves me wrong Im happy to change my opinion. I dont recall ever hearing about anyone finding a problem with scrubber during pre breathe and I do recall people whos unit passed pre breaths then they had breakthrough on descent.... I agree fully that there is no need to do again a pre-breath when you did it an hour ago, and you did not change anything on your unit paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
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28th March 2008, 14:08	#45 (permalink)
JonnyB Jonny The Hatch Current Rebreather/s: MK 15.X Titan Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Megalodon Sport Kiss Classic Kiss Home Build Join Date: Jan 2005 Location: Sweden (Stockholm)/Cyprus(Ayia Napa) Posts: 940	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by Drmike) be easy to do seeing as the temp is known Then you introduce another failpoint. you would need some other kind of sensor (read termometer) that can tell you accurate temperature and you would need to build logic into the unit that uses this. I have seen these temperatures to vary a lot from one second to the other. And I would not want any type of pre dive procedure to be evaluated on the fly. What's next, people diving in the arctis putting their handset in hot water just so they dont have to do the 5 minutes of pre breath? People are stupid and they will do stupid things. Plan your dive and time. And dive accordingly. just my $0.02 Jonny __________________ A quote from Crazyduck - In remembering our own Rob Davies. "Outbound flight 777 heavy you are cleared for flight Due west into that warm red Texas sunset You have angels on your wings and divers memories on your six." Rest In Peace http://www.divetekcyprus.com http://www.diveccr.com
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28th March 2008, 23:17	#46 (permalink)
tecdivertraining RebreatherWorld Sponsor Current Rebreather/s: Inspiration Classic Inspiration Vision Evolution Megalodon Dolphin Other Rebreather/s: Not Bought Yet Dolphin Join Date: May 2005 Location: Phuket, Thailand Posts: 398	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by paulraymaekers) Hello Matt, if you can breath 10 minutes from a unit with NO scrubber inside, withouth any signs.. paul Hi paul on all Mix courses I have students remove their scrubbers and breath from their units obviously with the O2 on and wearing a mask I have yet to have one detect CO2 before 5 mins. try it and let me know how you go. __________________ Mathew Partridge Technical Director Pro-Tech Dive College www.protechdivers.com www.tech-ccr.com
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29th March 2008, 02:04	#47 (permalink)
KevDD Custom Title Allowed! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Oct 2005 Location: Dublin, Ireland Posts: 105	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by tecdivertraining) Hi paul on all Mix courses I have students remove their scrubbers and breath from their units obviously with the O2 on and wearing a mask I have yet to have one detect CO2 before 5 mins. try it and let me know how you go. I did the same experiment and it took at least 4-5 mins before co2 build up became evident. This may however be accelerated by depth? The point does still remain that the prebreath may not show anything even thought co2 is breaking through (depends how long you pre breathe it for ofcourse).
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29th March 2008, 07:16	#48 (permalink)
Mikel-Deko Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Other CCR Join Date: Jul 2005 Location: Basque Country -Sp- Posts: 410	Re: Sentinel LSS - Trip Report Maybe instead O2 if you breathe say EAN30 without the scrubber, you will detectec the CO2 earlier. Just an idea... Best Mikel __________________ Mikel-Deko Basque Country www.olatu.net "DIR is the nanny state for divers who cannot think on their own" Ron Micjan
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29th March 2008, 10:02	#49 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,128	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by tecdivertraining) Hi paul on all Mix courses I have students remove their scrubbers and breath from their units obviously with the O2 on and wearing a mask I have yet to have one detect CO2 before 5 mins. try it and let me know how you go. thanks buddy, so its all tosh then...damn that 5min pre breathe is really gonna buy me now __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you
(Offline)

29th March 2008, 10:05	#50 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,128	Re: Sentinel LSS - Trip Report Quote: (Originally Posted by JonnyB) Then you introduce another failpoint. you would need some other kind of sensor (read termometer) that can tell you accurate temperature and you would need to build logic into the unit that uses this. I have seen these temperatures to vary a lot from one second to the other. And I would not want any type of pre dive procedure to be evaluated on the fly. What's next, people diving in the arctis putting their handset in hot water just so they dont have to do the 5 minutes of pre breath? People are stupid and they will do stupid things. Plan your dive and time. And dive accordingly. just my $0.02 Jonny scrubber temp is known - as in thermister is already built in to each unit and loop gas temp is already measured. Piece of cake programming wise to just reduce the pre breasthe period to suit the loop temp, afterall the only way to cheat (increase) the loop temp is to pre breathe __________________ Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you
(Offline)

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