I'd read somewhere that our recommended limits were got by NOAA deciding the safe limits, then halving it.
WRT to PO2, again when I learnt you were told 1.6 was the max , but to reduce by 0.05 for each of the following, cold, dark/stress and exertion, which brings you pretty close to BS-AC's 1.44. But then that's not really surprising when you think where the BS-ACs recommendations came from.
As with a lot of things, knowing why we do something is more important then know what to do by rote.
As Iain said, the original work is Kenneth Donald's, I'm not sure if there been any more experimentation since, or whether it's all extrapolation and fudge factors based on his work.
Finally, a lot of what we get as recreational divers is old and 2nd hand because to the people paying for the research, (Comex et al.) this stuff has a commercial value.
WRT to PO2, again when I learnt you were told 1.6 was the max , but to reduce by 0.05 for each of the following, cold, dark/stress and exertion, which brings you pretty close to BS-AC's 1.44. But then that's not really surprising when you think where the BS-ACs recommendations came from.
As with a lot of things, knowing why we do something is more important then know what to do by rote.
As Iain said, the original work is Kenneth Donald's, I'm not sure if there been any more experimentation since, or whether it's all extrapolation and fudge factors based on his work.
Finally, a lot of what we get as recreational divers is old and 2nd hand because to the people paying for the research, (Comex et al.) this stuff has a commercial value.
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