Use of 'hot' diluents

uri · 28th January 2007, 18:26

I've been having a debate with a mate about the use of 18/40 to depths of 90 metres or so. It follows on from a thread on Rebreather World where Dave Sutton suggested that a couple of minutes on a ppo2 a few tenths of a bar above 1.6 is less risky than using a diluent that would be hypoxic on the surface.

The gist of my viewpoint is that the only time one actually gets the full pp02 from the dil is if one has to do a full loop flush and that would be rapidly breathed down added to the fact that one would probably ascend anyway to reduce the pp02.

The other view is that one is injecting the 18/40 all the way down anyway to keep minimum/constant loop volume and that this would tend to keep the pp02 too high for too long.

It seems to me that with a low setpoint, it's very unlikely that injecting 18/40 on the way down (even to 90m) would spike the pp02 above 1.6 letalone keep a pp02 that was above 1.6 (or even close to it) for any length of time. I also can't see why topping up the loop volume on the bottom with 18/40 would cause serious problems since the bulk of the gas already in the loop at this point would be at high setpoint of say 1.3 and the amount added would be a small perecentage of that already there so the effect on the total loop would be minimal.

Does anyone have any views on which is the more accurate perspective?

U.

chunter · 28th January 2007, 19:02

Quote: (Originally Posted by uri)

I've been having a debate with a mate about the use of 18/40 to depths of 90 metres or so. It follows on from a thread on Rebreather World where Dave Sutton suggested that a couple of minutes on a ppo2 a few tenths of a bar above 1.6 is less risky than using a diluent that would be hypoxic on the surface.

The gist of my viewpoint is that the only time one actually gets the full pp02 from the dil is if one has to do a full loop flush and that would be rapidly breathed down added to the fact that one would probably ascend anyway to reduce the pp02.

The other view is that one is injecting the 18/40 all the way down anyway to keep minimum/constant loop volume and that this would tend to keep the pp02 too high for too long.

It seems to me that with a low setpoint, it's very unlikely that injecting 18/40 on the way down (even to 90m) would spike the pp02 above 1.6 letalone keep a pp02 that was above 1.6 (or even close to it) for any length of time. I also can't see why topping up the loop volume on the bottom with 18/40 would cause serious problems since the bulk of the gas already in the loop at this point would be at high setpoint of say 1.3 and the amount added would be a small perecentage of that already there so the effect on the total loop would be minimal.

Does anyone have any views on which is the more accurate perspective?

U.

I dive with a low O2 mix (10/50tx) on deep dives for three reasons:

1) Practical application - It allows me to dive a standardized mix regardless of whether I'm diving to 200' or 400'. I have the same bailout tables, and I know the schedules roughly in my head. If I'm at 250' and see somthing a bit deeper, I can drop down without having to worry about a PO2 spike. The difference in OC bailout times between 10/50 or 18/50 are minimal, especially if you carry another nitrox mix.

2) A hypoxic mix doesn't bother me on CCR - It makes no difference to me if the mix is hypoxic at the surface because I can pre-breathe with it at my low setpoint with no problems, and I can go from the surface to the bottom on the mix. If I were to bail out, it wouldn't matter that I was using a hypoxic mix because I would likely have a nitrox mix with me as well (50%). Even if I lost that tank, I could use the 10/50 tx to 33 feet, and then switch to O2 while I worked my way up to 20 feet.

3) PO2 Spikes & Diluent Flushes - I have tried flushing down my loop in a high O2 situation with 18/50 tx, and it takes forever. The only realistic option is to go OC and blow into the loop. If you were to have a solenoid stuck open, or hit your manual O2 add by accident, flushing is nearly useless.

I just don't see the benefit of using a high O2 diluent. Yes, we can push the CNS clock, probably without incident, but why?

Aloha,
Charlie

**Dave Sutton** · 28th January 2007, 19:59

Gack............

I guess we need to start this all over again.....

How long does it take to breathe down a 1.6 PP02 loop to 1.2? Answer that and you'll see that the CNS clock that you're talking about is an order of magnitude longer than any time exposure to higher than setpoint PP02 as articulated in my earlier set of posts.

Your idea of switching to 02 for the last 33 feet is great.... as long as you have access to the 02. I make no such assumptions. The carriage of many moles of 02 is mainly for on-loop bailout tactics. Re-read the earlier discusion *completely* and all the points will be made.

Dave

Depth-junkie · 28th January 2007, 20:40

Quote: (Originally Posted by uri)

I've been having a debate with a mate about the use of 18/40 to depths of 90 metres or so. It follows on from a thread on Rebreather World where Dave Sutton suggested that a couple of minutes on a ppo2 a few tenths of a bar above 1.6 is less risky than using a diluent that would be hypoxic on the surface.

The gist of my viewpoint is that the only time one actually gets the full pp02 from the dil is if one has to do a full loop flush and that would be rapidly breathed down added to the fact that one would probably ascend anyway to reduce the pp02.

The other view is that one is injecting the 18/40 all the way down anyway to keep minimum/constant loop volume and that this would tend to keep the pp02 too high for too long.

It seems to me that with a low setpoint, it's very unlikely that injecting 18/40 on the way down (even to 90m) would spike the pp02 above 1.6 letalone keep a pp02 that was above 1.6 (or even close to it) for any length of time. I also can't see why topping up the loop volume on the bottom with 18/40 would cause serious problems since the bulk of the gas already in the loop at this point would be at high setpoint of say 1.3 and the amount added would be a small perecentage of that already there so the effect on the total loop would be minimal.

Does anyone have any views on which is the more accurate perspective?

U.

18% 02 @ 90m in my book is 1.8 pp02, bit to hot for me M8.

If you think that you would breath the loop down quick enough whilst descending & puling gas through the ADV or man-inflators, be my guest but it's not something i would even contemplate doing.

And thats not without getting to Dil flushes or big breaths due to work load etc.

ATB
Gareth

***ScubaDadMiami*** · 28th January 2007, 22:29

Suppose you get stuck on the bottom for one reason or another, or suppose something happens to pull you deeper than your planned depth?

chunter · 28th January 2007, 23:07

Quote: (Originally Posted by Dave Sutton)

Gack............

I guess we need to start this all over again.....

How long does it take to breathe down a 1.6 PP02 loop to 1.2?

Dave

I realize that the last time this came up it was discussed in length. In the end, all of this comes down to personal preferance. Frankly, I was bored sensless after the first 18 pages of the other debate.

To answer your question, it takes me at least 4 minutes to breathe down a 1.6 to a 1.2 (assuming I'm not on my KISS, which would take forever unless I shut off my O2). Unless you have the VO2 of an ox, I can't imagine it takes you much less. Besides, it's not the 1.6 I'm worried about. The real question is how long does it take you to breathe down a 2.5 to a 1.3 or better yet, to flush a 4.0 down to a 1.3? I'm guessing at least half the length of your bottom time.

It was just yesterday that my buddy had to go SCC on his inspo (when we both had an hour of deco remaining), and he woudn't have had any significantly shorter deco on 18/50 than on 10/50. In fact, his deco ended nearly exactly with mine, and I was at a 1.3 the whole time.

Aloha,
C

**Dave Sutton** · 28th January 2007, 23:46

Quote: (Originally Posted by ScubaDadMiami)

Suppose you get stuck on the bottom for one reason or another, or suppose something happens to pull you deeper than your planned depth?

Suppose this, suppose that, suppose the next thing. The thing is that the armchair "what if" and "I'm gonna die if I see 1.8 for 5 minutes" theories don't jive with reality. Anyone can make up all the excuses they like, but what works, works. This works.

Pull deeper than planned depth? Pulled by what, giant squid?

Stuck on the bottom? Never been "stuck on the bottom" (well, OK, there *was* that time in the mud of the harbor using a Mark-V deep sea helmet rig, but that's another story for a different day....)

It's obvious that you don't understand the POINT: That the loop PP02 will be DROPPING IMMEDIATELY as you consume the 02 after you reach the bottom. Does anyone really think that *diluent* PP02 sets FINAL PP02 on the bottom? Only for a minute, not longer. Think this over: In a *very few minutes* the loop PP02 will be at less than setpoint if you don't add 02... and with an ECCR the loop will fall to setpoint in a VERY FEW MINUTES and then you'll be right where you wanted to be all along. CNS clock? Give me a break.

This all seems like remedial CCR training 101.... who's giving training whereby divers miss these points in basic training ??? No offense meant, but lack of knowlage of these basic principles scares me.

Best,

Dave

**Dave Sutton** · 28th January 2007, 23:52

Quote: (Originally Posted by chunter)

I The real question is how long does it take you to breathe down a 2.5 to a 1.3 or better yet, to flush a 4.0 down to a 1.3?

Errr..... *nobody* ever suggested diving with a diluent that had a 2.5 or 4.0 PP02 on the bottom so *get real*. Any point can be taken to the area of senselessness. What I *suggested* is that we not switch to hypoxic diluents *unless we need them* and then further suggested that we don't need them as shallow as some think. I fence off my max depth for normoxic diluents when I reach 1.8 PP02 on the bottom, and run 20% dils to the associated depths for that. After that we switch to hypoxic dils. And it's *darned rare* for us to be in the depth band where we exceed setpoint PP02 with 20% and have not yet switched to hypoxic dils. Like 1 in 100 dives......

2.5? 4.0? Nobody ever said that was appropriate. Maybe you got bored and skipped over the technical parts in the earlier series.... and the KISS has a valve on the 02 bottle for a reason......

And the title of the thread is wrong:

NOBODY INCLUDING ME HAS PROPOSED THE DELIBERATE USE OF HOT DILUENTS.

Can I make it any clearer than that?

All I have EVER said is that we should not use hypoxic diluents *unless required* as they:

(1) disallow us certain important SCC bailout modes,

(2) hurt our deco possibilities using our dil open circuit,

(3) have hypoxia/drowning potential if an ADV fails open or we get unwanted diluent into the loop near the surface (and read the current Inspiration thread on that issue it's a REAL one...). And no joke: With the reports of undesired diluent freeflows into the loop, this could KILL YOU RIGHT NOW!

GUYS: If you get an ADV freeflow, (which is *far* more common than many other "silly bordering on insane" hypotheticals than people propose here,) you're not gonna tolerate 10% diluent in your loop on the surface for more than a few *moments* before doing the dead-fly routine *just moments before you drown* after your DSV slips from your unconcious mouth and you loose all of that nice bouyancy in the loop as it floods in about 5 seconds... Trust me on this, *please*?? as I've seen it for *real* (except we dived in and saved his sorry butt and now he buys me beer and mixes his 20% diluent with a smile)

etc.

I also *mentioned* that I will *TOLERATE* (not "desire") diluent that is SLIGHTLY hotter than my desired setpoint *for a certain small fraction of my dives* before I switch to hypoxic diluents for the aformentioned reasons, as I will reduce the PP02 by normal metabolism LONG BEFORE THE CNS CLOCK does jack-shi@ to me. I *personally* use 1.8 as my cut-off, feel free to use 1.6 or 1.4, whatever runs your CNS clock.... Get it?

Dave

chunter · 29th January 2007, 04:49

Quote: (Originally Posted by Dave Sutton)

Errr..... *nobody* ever suggested diving with a diluent that had a 2.5 or 4.0 PP02 on the bottom so *get real*.

Dave

I wasn't suggesting that anyone would plan for that, but solenoids do get stuck open, and people have injected O2 by accident.

As to the ADV...it's pretty easy to turn off a diluent valve or have a shut-off to prevent going hypoxic.

Dive what you like. I think both sides of this debate have been more than covered. I must say though, your ranting is somewhat offensive. Gack...errr...*get real*...get it?

Aloha,
Charlie

***EBT*** · 29th January 2007, 08:02

Quote: (Originally Posted by Dave Sutton)

Gack............

Yep.... my thoughts too

Quote: (Originally Posted by dave sutton)

I guess we need to start this all over again.....

Aaaargh! Really? I thought both sides made their points more than adequately in that huge tome of posts

28th January 2007, 18:26	#1 (permalink)
uri Uri Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Apr 2005 Location: Sandhurst UK Posts: 37	Use of 'hot' diluents I've been having a debate with a mate about the use of 18/40 to depths of 90 metres or so. It follows on from a thread on Rebreather World where Dave Sutton suggested that a couple of minutes on a ppo2 a few tenths of a bar above 1.6 is less risky than using a diluent that would be hypoxic on the surface. The gist of my viewpoint is that the only time one actually gets the full pp02 from the dil is if one has to do a full loop flush and that would be rapidly breathed down added to the fact that one would probably ascend anyway to reduce the pp02. The other view is that one is injecting the 18/40 all the way down anyway to keep minimum/constant loop volume and that this would tend to keep the pp02 too high for too long. It seems to me that with a low setpoint, it's very unlikely that injecting 18/40 on the way down (even to 90m) would spike the pp02 above 1.6 letalone keep a pp02 that was above 1.6 (or even close to it) for any length of time. I also can't see why topping up the loop volume on the bottom with 18/40 would cause serious problems since the bulk of the gas already in the loop at this point would be at high setpoint of say 1.3 and the amount added would be a small perecentage of that already there so the effect on the total loop would be minimal. Does anyone have any views on which is the more accurate perspective? U.
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28th January 2007, 19:02	#2 (permalink)
chunter I like diving Current Rebreather/s: Sport Kiss MK 15.X Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Classic Kiss Join Date: Jul 2006 Location: Honolulu Posts: 463	Re: Use of 'hot' diluents Quote: (Originally Posted by uri) I've been having a debate with a mate about the use of 18/40 to depths of 90 metres or so. It follows on from a thread on Rebreather World where Dave Sutton suggested that a couple of minutes on a ppo2 a few tenths of a bar above 1.6 is less risky than using a diluent that would be hypoxic on the surface. The gist of my viewpoint is that the only time one actually gets the full pp02 from the dil is if one has to do a full loop flush and that would be rapidly breathed down added to the fact that one would probably ascend anyway to reduce the pp02. The other view is that one is injecting the 18/40 all the way down anyway to keep minimum/constant loop volume and that this would tend to keep the pp02 too high for too long. It seems to me that with a low setpoint, it's very unlikely that injecting 18/40 on the way down (even to 90m) would spike the pp02 above 1.6 letalone keep a pp02 that was above 1.6 (or even close to it) for any length of time. I also can't see why topping up the loop volume on the bottom with 18/40 would cause serious problems since the bulk of the gas already in the loop at this point would be at high setpoint of say 1.3 and the amount added would be a small perecentage of that already there so the effect on the total loop would be minimal. Does anyone have any views on which is the more accurate perspective? U. I dive with a low O2 mix (10/50tx) on deep dives for three reasons: 1) Practical application - It allows me to dive a standardized mix regardless of whether I'm diving to 200' or 400'. I have the same bailout tables, and I know the schedules roughly in my head. If I'm at 250' and see somthing a bit deeper, I can drop down without having to worry about a PO2 spike. The difference in OC bailout times between 10/50 or 18/50 are minimal, especially if you carry another nitrox mix. 2) A hypoxic mix doesn't bother me on CCR - It makes no difference to me if the mix is hypoxic at the surface because I can pre-breathe with it at my low setpoint with no problems, and I can go from the surface to the bottom on the mix. If I were to bail out, it wouldn't matter that I was using a hypoxic mix because I would likely have a nitrox mix with me as well (50%). Even if I lost that tank, I could use the 10/50 tx to 33 feet, and then switch to O2 while I worked my way up to 20 feet. 3) PO2 Spikes & Diluent Flushes - I have tried flushing down my loop in a high O2 situation with 18/50 tx, and it takes forever. The only realistic option is to go OC and blow into the loop. If you were to have a solenoid stuck open, or hit your manual O2 add by accident, flushing is nearly useless. I just don't see the benefit of using a high O2 diluent. Yes, we can push the CNS clock, probably without incident, but why? Aloha, Charlie
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28th January 2007, 19:59	#3 (permalink)
Dave Sutton Living on Animal Farm Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Classic Kiss rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,512	Re: Use of 'hot' diluents Gack............ I guess we need to start this all over again..... How long does it take to breathe down a 1.6 PP02 loop to 1.2? Answer that and you'll see that the CNS clock that you're talking about is an order of magnitude longer than any time exposure to higher than setpoint PP02 as articulated in my earlier set of posts. Your idea of switching to 02 for the last 33 feet is great.... as long as you have access to the 02. I make no such assumptions. The carriage of many moles of 02 is mainly for on-loop bailout tactics. Re-read the earlier discusion completely and all the points will be made. Dave __________________ . "All animals are equal, but some animals are more equal than others" Professional Small Boy: Never Successfully Cubicled.
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28th January 2007, 20:40	#4 (permalink)
Depth-junkie 10/52 Psycho Current Rebreather/s: Inspiration Vision Other Rebreather/s: Join Date: Aug 2005 Location: Wrexham Posts: 288	Re: Use of 'hot' diluents Quote: (Originally Posted by uri) I've been having a debate with a mate about the use of 18/40 to depths of 90 metres or so. It follows on from a thread on Rebreather World where Dave Sutton suggested that a couple of minutes on a ppo2 a few tenths of a bar above 1.6 is less risky than using a diluent that would be hypoxic on the surface. The gist of my viewpoint is that the only time one actually gets the full pp02 from the dil is if one has to do a full loop flush and that would be rapidly breathed down added to the fact that one would probably ascend anyway to reduce the pp02. The other view is that one is injecting the 18/40 all the way down anyway to keep minimum/constant loop volume and that this would tend to keep the pp02 too high for too long. It seems to me that with a low setpoint, it's very unlikely that injecting 18/40 on the way down (even to 90m) would spike the pp02 above 1.6 letalone keep a pp02 that was above 1.6 (or even close to it) for any length of time. I also can't see why topping up the loop volume on the bottom with 18/40 would cause serious problems since the bulk of the gas already in the loop at this point would be at high setpoint of say 1.3 and the amount added would be a small perecentage of that already there so the effect on the total loop would be minimal. Does anyone have any views on which is the more accurate perspective? U. 18% 02 @ 90m in my book is 1.8 pp02, bit to hot for me M8. If you think that you would breath the loop down quick enough whilst descending & puling gas through the ADV or man-inflators, be my guest but it's not something i would even contemplate doing. And thats not without getting to Dil flushes or big breaths due to work load etc. ATB Gareth Last edited by Depth-junkie : 28th January 2007 at 20:43.
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28th January 2007, 22:29	#5 (permalink)
*ScubaDadMiami* Moderator Current Rebreather/s: Optima Other Rebreather/s: Join Date: Sep 2005 Location: Florida, USA Posts: 1,939	Re: Use of 'hot' diluents Suppose you get stuck on the bottom for one reason or another, or suppose something happens to pull you deeper than your planned depth? __________________ Howard Packer IANTD CCR Instructor Miami Beach, Florida CCRDiveTraining.com
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28th January 2007, 23:07	#6 (permalink)
chunter I like diving Current Rebreather/s: Sport Kiss MK 15.X Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Classic Kiss Join Date: Jul 2006 Location: Honolulu Posts: 463	Re: Use of 'hot' diluents Quote: (Originally Posted by Dave Sutton) Gack............ I guess we need to start this all over again..... How long does it take to breathe down a 1.6 PP02 loop to 1.2? Dave I realize that the last time this came up it was discussed in length. In the end, all of this comes down to personal preferance. Frankly, I was bored sensless after the first 18 pages of the other debate. To answer your question, it takes me at least 4 minutes to breathe down a 1.6 to a 1.2 (assuming I'm not on my KISS, which would take forever unless I shut off my O2). Unless you have the VO2 of an ox, I can't imagine it takes you much less. Besides, it's not the 1.6 I'm worried about. The real question is how long does it take you to breathe down a 2.5 to a 1.3 or better yet, to flush a 4.0 down to a 1.3? I'm guessing at least half the length of your bottom time. It was just yesterday that my buddy had to go SCC on his inspo (when we both had an hour of deco remaining), and he woudn't have had any significantly shorter deco on 18/50 than on 10/50. In fact, his deco ended nearly exactly with mine, and I was at a 1.3 the whole time. Aloha, C
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28th January 2007, 23:46	#7 (permalink)
Dave Sutton Living on Animal Farm Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Classic Kiss rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,512	Re: Use of 'hot' diluents Quote: (Originally Posted by ScubaDadMiami) Suppose you get stuck on the bottom for one reason or another, or suppose something happens to pull you deeper than your planned depth? Suppose this, suppose that, suppose the next thing. The thing is that the armchair "what if" and "I'm gonna die if I see 1.8 for 5 minutes" theories don't jive with reality. Anyone can make up all the excuses they like, but what works, works. This works. Pull deeper than planned depth? Pulled by what, giant squid? Stuck on the bottom? Never been "stuck on the bottom" (well, OK, there was that time in the mud of the harbor using a Mark-V deep sea helmet rig, but that's another story for a different day....) It's obvious that you don't understand the POINT: That the loop PP02 will be DROPPING IMMEDIATELY as you consume the 02 after you reach the bottom. Does anyone really think that diluent PP02 sets FINAL PP02 on the bottom? Only for a minute, not longer. Think this over: In a very few minutes the loop PP02 will be at less than setpoint if you don't add 02... and with an ECCR the loop will fall to setpoint in a VERY FEW MINUTES and then you'll be right where you wanted to be all along. CNS clock? Give me a break. This all seems like remedial CCR training 101.... who's giving training whereby divers miss these points in basic training ??? No offense meant, but lack of knowlage of these basic principles scares me. Best, Dave __________________ . "All animals are equal, but some animals are more equal than others" Professional Small Boy: Never Successfully Cubicled.
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28th January 2007, 23:52	#8 (permalink)
Dave Sutton Living on Animal Farm Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Classic Kiss rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,512	Re: Use of 'hot' diluents Quote: (Originally Posted by chunter) I The real question is how long does it take you to breathe down a 2.5 to a 1.3 or better yet, to flush a 4.0 down to a 1.3? Errr..... nobody ever suggested diving with a diluent that had a 2.5 or 4.0 PP02 on the bottom so get real. Any point can be taken to the area of senselessness. What I suggested is that we not switch to hypoxic diluents unless we need them and then further suggested that we don't need them as shallow as some think. I fence off my max depth for normoxic diluents when I reach 1.8 PP02 on the bottom, and run 20% dils to the associated depths for that. After that we switch to hypoxic dils. And it's darned rare for us to be in the depth band where we exceed setpoint PP02 with 20% and have not yet switched to hypoxic dils. Like 1 in 100 dives...... 2.5? 4.0? Nobody ever said that was appropriate. Maybe you got bored and skipped over the technical parts in the earlier series.... and the KISS has a valve on the 02 bottle for a reason...... And the title of the thread is wrong: NOBODY INCLUDING ME HAS PROPOSED THE DELIBERATE USE OF HOT DILUENTS. Can I make it any clearer than that? All I have EVER said is that we should not use hypoxic diluents unless required as they: (1) disallow us certain important SCC bailout modes, (2) hurt our deco possibilities using our dil open circuit, (3) have hypoxia/drowning potential if an ADV fails open or we get unwanted diluent into the loop near the surface (and read the current Inspiration thread on that issue it's a REAL one...). And no joke: With the reports of undesired diluent freeflows into the loop, this could KILL YOU RIGHT NOW! GUYS: If you get an ADV freeflow, (which is far more common than many other "silly bordering on insane" hypotheticals than people propose here,) you're not gonna tolerate 10% diluent in your loop on the surface for more than a few moments before doing the dead-fly routine just moments before you drown after your DSV slips from your unconcious mouth and you loose all of that nice bouyancy in the loop as it floods in about 5 seconds... Trust me on this, please?? as I've seen it for real (except we dived in and saved his sorry butt and now he buys me beer and mixes his 20% diluent with a smile) etc. I also mentioned that I will TOLERATE (not "desire") diluent that is SLIGHTLY hotter than my desired setpoint for a certain small fraction of my dives before I switch to hypoxic diluents for the aformentioned reasons, as I will reduce the PP02 by normal metabolism LONG BEFORE THE CNS CLOCK does jack-shi@ to me. I personally use 1.8 as my cut-off, feel free to use 1.6 or 1.4, whatever runs your CNS clock.... Get it? Dave __________________ . "All animals are equal, but some animals are more equal than others" Professional Small Boy: Never Successfully Cubicled. Last edited by Dave Sutton : 29th January 2007 at 00:13.
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29th January 2007, 04:49	#9 (permalink)
chunter I like diving Current Rebreather/s: Sport Kiss MK 15.X Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Classic Kiss Join Date: Jul 2006 Location: Honolulu Posts: 463	Re: Use of 'hot' diluents Quote: (Originally Posted by Dave Sutton) Errr..... nobody ever suggested diving with a diluent that had a 2.5 or 4.0 PP02 on the bottom so get real. Dave I wasn't suggesting that anyone would plan for that, but solenoids do get stuck open, and people have injected O2 by accident. As to the ADV...it's pretty easy to turn off a diluent valve or have a shut-off to prevent going hypoxic. Dive what you like. I think both sides of this debate have been more than covered. I must say though, your ranting is somewhat offensive. Gack...errr...get real...get it? Aloha, Charlie Last edited by chunter : 29th January 2007 at 04:51.
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29th January 2007, 08:02	#10 (permalink)
*EBT* Apprentice Luddite Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: UK, Brighton Posts: 1,855	Re: Use of 'hot' diluents Quote: (Originally Posted by Dave Sutton) Gack............ Yep.... my thoughts too Quote: (Originally Posted by dave sutton) I guess we need to start this all over again..... Aaaargh! Really? I thought both sides made their points more than adequately in that huge tome of posts __________________ Eagles May Soar, but weasels don't get sucked into jet engines! Rebreather World Terms of service Real diving t-shirts for real divers Last edited by EBT : 29th January 2007 at 21:23.
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