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***jradomski*** · 11th January 2007, 10:28

Quote: (Originally Posted by RonMicjan)

not even close, there is not nearly the PPn2 in the loop until you get to the "matching" depth, do the math and see what the PPn2 is at various depths at a constant setpoint.

Any one who tells you that oxygen is as narcotic as nitrogen has never dived a CCR, try this experiment, take your unit to depth with a low setpoint, say 130fsw and a sp of .4, (you will have to sit and breathe it down a while) think about your narcotic level, estimate the level of "fog", "rapture" "stupidity" or whatever version of narcosis you personally feel. Then, bump the PO2 up to 1.4 or so and watch the fog roll away, like your sittin on the dock o' the bay. Of course, dont be hangin around at 130 on a .4 too long, and make sure you are tracking deco with a dive computer set to whatever you are breathing.

next experiement, do the same drill and after the loop is resting at .4, then flush the loop with 20/50 and REALLY see the fog roll away. air for dil? NOT!

out of curiosity, why the twenty questions on narcosis?

BTW, I have done air OC to 276, had an awesome encounter with an electric ray (at least I think I did

) back when I was young and stupid. Now air OC is limited to OW instruction depths and shallow salvage and body recovery dives. The vast majority of diving is done CCR on 20/30 to about 150ish and 10/50 deeper. I like to keep an END of around 100fsw or PN2 of 3.2 ish.

HELIUM is your FRIEND!

I usually do this with people a bit deeper, usually around 150fsw, since you dont have to breath the loop down as much to get a good narc, then bringing it up to 1.4ish makes a big difference even though it doesnt fully clear up for many divers..

I'm not going to say oxygen is not narcotic at all, but I am willing to say its considerably less than the nitrogen it is replacing..

This is something than can easily be experienced by CCR divers, All the OC divers that say o2 narcosis is the same as n2 narcosic have never done an experiment that can easily prove this is the case, unfortunately we cant measure how narcotic the o2 is, but my feeling is is that the narcosis contribution by oxygen is so low that treating it as non narcotic reaaly isnt a problem, unless you are right on the edge for the depth your at....

11th January 2007, 10:28	#34 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,093	Re: Deep air on OC vs. CCR Quote: (Originally Posted by RonMicjan) not even close, there is not nearly the PPn2 in the loop until you get to the "matching" depth, do the math and see what the PPn2 is at various depths at a constant setpoint. Any one who tells you that oxygen is as narcotic as nitrogen has never dived a CCR, try this experiment, take your unit to depth with a low setpoint, say 130fsw and a sp of .4, (you will have to sit and breathe it down a while) think about your narcotic level, estimate the level of "fog", "rapture" "stupidity" or whatever version of narcosis you personally feel. Then, bump the PO2 up to 1.4 or so and watch the fog roll away, like your sittin on the dock o' the bay. Of course, dont be hangin around at 130 on a .4 too long, and make sure you are tracking deco with a dive computer set to whatever you are breathing. next experiement, do the same drill and after the loop is resting at .4, then flush the loop with 20/50 and REALLY see the fog roll away. air for dil? NOT! out of curiosity, why the twenty questions on narcosis? BTW, I have done air OC to 276, had an awesome encounter with an electric ray (at least I think I did ) back when I was young and stupid. Now air OC is limited to OW instruction depths and shallow salvage and body recovery dives. The vast majority of diving is done CCR on 20/30 to about 150ish and 10/50 deeper. I like to keep an END of around 100fsw or PN2 of 3.2 ish. HELIUM is your FRIEND! I usually do this with people a bit deeper, usually around 150fsw, since you dont have to breath the loop down as much to get a good narc, then bringing it up to 1.4ish makes a big difference even though it doesnt fully clear up for many divers.. I'm not going to say oxygen is not narcotic at all, but I am willing to say its considerably less than the nitrogen it is replacing.. This is something than can easily be experienced by CCR divers, All the OC divers that say o2 narcosis is the same as n2 narcosic have never done an experiment that can easily prove this is the case, unfortunately we cant measure how narcotic the o2 is, but my feeling is is that the narcosis contribution by oxygen is so low that treating it as non narcotic reaaly isnt a problem, unless you are right on the edge for the depth your at.... __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated. Last edited by jradomski : 11th January 2007 at 10:32.
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