Very nice discussion.
On the original topic I have a couple things to add I did not notice posted. Since the basic principle of the scrubber is that a CO2 molecule must impact the scrubber material to get a reaction (bonding), The density of the gas passing through the scrubber can/will affect the opportunity of the CO2 molecules actually contacting. This is because the other molecules of N2, O2 etc insulate the CO2 to some extent. Hence one of the reasons dwell time is important, aka time and opportunity. This is why deep dives are done on fresh scrubbers to maximize the dwell time. When confronted with heavy work loads there are times I may bail out temporarily just to be on the safe side. And I'm very careful (now) to get off the loop on the surface if I have nearly used up my scrubber or if I am having to swim hard, or am using a hypoxic Dil.
Another point is that the capacity of the divers lungs and the rate of flow relative to the total loop volume can affect the dwell time as the rate of flow and increased pressure from breathing hard can further reduce the dwell time. I've twice over breathed the EAC cartridge in my Optima resulting in hypercapnia hits; fortunately I was luckly, but a trip to the doctors office confirmed I have very large lungs. So now I choose which RB I use for the dive is in part looking at what my work load may be.
On the original topic I have a couple things to add I did not notice posted. Since the basic principle of the scrubber is that a CO2 molecule must impact the scrubber material to get a reaction (bonding), The density of the gas passing through the scrubber can/will affect the opportunity of the CO2 molecules actually contacting. This is because the other molecules of N2, O2 etc insulate the CO2 to some extent. Hence one of the reasons dwell time is important, aka time and opportunity. This is why deep dives are done on fresh scrubbers to maximize the dwell time. When confronted with heavy work loads there are times I may bail out temporarily just to be on the safe side. And I'm very careful (now) to get off the loop on the surface if I have nearly used up my scrubber or if I am having to swim hard, or am using a hypoxic Dil.
Another point is that the capacity of the divers lungs and the rate of flow relative to the total loop volume can affect the dwell time as the rate of flow and increased pressure from breathing hard can further reduce the dwell time. I've twice over breathed the EAC cartridge in my Optima resulting in hypercapnia hits; fortunately I was luckly, but a trip to the doctors office confirmed I have very large lungs. So now I choose which RB I use for the dive is in part looking at what my work load may be.