| There are different equations for different rebreathers depending on passive or active SCR, addition rate or dump rate, drive gas, depth etc., which will allow you to estimate what is in your loop.
Work out what you will be breathing at the dive depth and plug your figures into deco software, treating it as open circuit.
Alternatively, plumb a VR3 or Explorer into the loop with an O2 sensor.
__________________ "I hate to advocate drugs, alcohol, violence or insanity to anyone, but they've always worked for me" Hunter S Thompson http://www.snp.org |