| Re: narcosis question.
Hmmmm two approaches;
- Approach 1. Residual loop CO2.
If there was residual CO2 in the loop, there would be enhanced CO2. We run the units within limits defined for the scrubber to ensure there is no residual loop CO2.
- Approach 2. Sticking to Air Dil.
Assuming a setpoint of 1.3 (for the sake of argument) and a dive depth of 40m (1.3/5), we get a loop FO2 of 26%, leading to 74% FN2. So, thats less narcotic than air. However if you take air dil deeper (say 60m... which should be trimix country but thats a different debate). Your loop FN2 @ 1.3 setpoint would be 81%. So thats more narcotic.
Both those approaches are very purist in view, but most of us chuck in a bucket load of helium (technical measurement), since its easy and cheap. So this sort of removes that whole narcosis debate, since we seem to be diving trimix at any depth. |