Quote: (Originally Posted by AD_ward9)
That is a good idea. We will put that in. Green blob again for that!
So, when you get to 90% CNS using the accelerated method, the system will tell you it is putting in an "Air break" and do just that, allowing the PPO2 to be breathed down to 0.4, until CNS drops to 85%, whereupon it will increase the PPO2 to your set point again.
You will need to breathe the loop down. This will take 10 to 12 minutes if you are on deco.
Any other suggestion on the limits? Should low point be 0.7?
Cheers,
Alex
Gotta go under 0.5 to get ANY credit for CNS according to NOAA.
Note that the usual practice on OC is to use the LOWEST FO2 gas you have (which is usually backgas); on 16/50, for example, an airbreak at 20' produces a roughly .25 PO2.
This would tend to argue for running even lower during an airbreak - perhaps to 0.3 - but I can see risk there too, because as the PO2 gets lower the reaction time for a LOW PO2 alarm goes down as well......
I am thinking 0.4 because that leaves you a reasonable margin before a failure to inject (e.g. low PO2) becomes critical, leaves you with the ability to ascend on the loop without injection in an emergency from 20' without risking the loop going hypoxic, and yet meets the < 0.5 critical point.