Thread: SAC - RB vs OC
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Old 14-04-08, 03:52 PM
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Unhappy SAC - RB vs OC

OK, so help me out here - by brain hurts thinking about this

My personal SAC for diving OC:
- relaxed / no heavy exercise : around 12-14 lpm
- stressed / heavy exercise : around 16-18 lpm

On the mCCR I have the constant flow set to about 1 lpm
- relaxed / no heavy exercise : ppO2 will rise
- stressed / heavy exercise : ppO2 will fall

So, lets assume that an O2 flow rate of 1 lpm is "my rate"
- a body metabolises 4% of air breathed, so...
- with an O2 usage of 1 lmp, my SAC would be 25 lpm

So, although (believe it or not), I'm more relaxed on mCCR than OC, my "SAC" is between 1.5 and 2.0 times that of OC

The questions therefore are:
- are my calcs wrong (for SAC mCCR usage)
- am I missing something
- is it that I have more gas available on mCCR so I use it?

please help put me out of my misery
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