Narcosis

[Inspirationdiver]

On the Inspiration there are two setpoints, one low and one high. The default values are .7 and 1.3 PO2. You use the low setpoint for the initial descent and then use the high setpoint at depth and then during the ascent. I've made descents to 100 ft at .7 PO2 and then switched to 1.3 when I got there. There is a big difference in narcosis between these two setpoints. Assuming I am not diving trimix, which means whatever is not oxygen is nitrogen, at 100 ft at .7 PO2 the breathing gas is 17.5 % oxygen and 82.5 % nitrogen. When I switch to the high setpoint it changes it to 32.5 % oxygen and 67.5 % nitrogen. This is a direct comparison between the narcotic effects of oxygen versus nitrogen. I can instantly tell when I change the setpoint.