Rebreather World - View Single Post - Think piece: rebreather breathing on the surface

womble · 16th October 2007, 21:57

Quote: (Originally Posted by warjarrett)

Are there dangers in breathing closed-circuit at the surface, that are greater than at depth? What is the concern, and why is it a bigger problem at the surface?

Breathing hypoxic diluents (<16% o2) at the surface with the O2 not turned on can be fatal, whereas at depth the rise in PPO2 will keep you alive, BUT ONLY IF YOU CONTINUALLY FLUSH THE LOOP WITH DIL (ie open loop or SCR)

Flushing the loop on the surface wont do anything as your PPO2 will still only be <0.16, not enough to sustain life.

If you dont flush the loop at depth, and your O2 is off, this will be just as fatal.

HTH

16th October 2007, 21:57	#2 (permalink)
womble Custom Title Allowed! Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2006 Location: UK Posts: 196	Re: Think piece: rebreather breathing on the surface Quote: (Originally Posted by warjarrett) Are there dangers in breathing closed-circuit at the surface, that are greater than at depth? What is the concern, and why is it a bigger problem at the surface? Breathing hypoxic diluents (<16% o2) at the surface with the O2 not turned on can be fatal, whereas at depth the rise in PPO2 will keep you alive, BUT ONLY IF YOU CONTINUALLY FLUSH THE LOOP WITH DIL (ie open loop or SCR) Flushing the loop on the surface wont do anything as your PPO2 will still only be <0.16, not enough to sustain life. If you dont flush the loop at depth, and your O2 is off, this will be just as fatal. HTH __________________ "What could possibly go wrong?? . . "
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