Rebreather World - View Single Post - Rate of PO2 drop changes with depth true/false

**fireman** · 24th December 2006, 22:28

Quote:

This is something I have seen quoted in a number of places including IANTD's training manual for MOD2.
As I see it this is WRONG! The number of molecules of O2 in the loop to acheive a PO2 of eg 1.3 at 10m is exactly the same as the number required to acheive the same PO2 at 110m.
Therefore given the same O2 consumption, the PO2 will decline at the same rate whatever the depth.
I'm concerned that people will be lulled into a false sense of security by thinking that their PO2 will drop slower at depth than they have seen/tested on the surface.

No I think you are mistaken: Much more oxygen is required assuming the volume of the loop is the same.

24th December 2006, 22:28	#2 (permalink)
fireman rEvo combat swimmer Current Rebreather/s: rEvo Other CCR Other Rebreather/s: rEvo Other CCR Join Date: Nov 2006 Location: chicago Posts: 518	Re: why do we do it? Quote: This is something I have seen quoted in a number of places including IANTD's training manual for MOD2. As I see it this is WRONG! The number of molecules of O2 in the loop to acheive a PO2 of eg 1.3 at 10m is exactly the same as the number required to acheive the same PO2 at 110m. Therefore given the same O2 consumption, the PO2 will decline at the same rate whatever the depth. I'm concerned that people will be lulled into a false sense of security by thinking that their PO2 will drop slower at depth than they have seen/tested on the surface. No I think you are mistaken: Much more oxygen is required assuming the volume of the loop is the same.
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