This is a question about the effectiveness of an O2 sensor in combination with a VR3 or HS Explorer.

I am thinking about purchasing one of these to use with my Drager.

Review/assumtions: Both the VR3 and the Explorer can be set up with an O2 sensor that mounts in a P-port on the inspiration bag. The advantage being that actual, inspired O2 is measured and used in decompression calculations. So far, so good.

I am currently using an Oxygauge to monitor pO2. I *think* I am seeing a decrease in sensitivity of the O2 cell as the dive progresses due to condensation in the loop. At the end of my dives my VO2 (metabolized O2)drops to zero, which obviously ain't happinin since I am still here.

I've checked calibration, and the gauge reads as expected at the begining with the supply gas and at the end of the dive after it is pulled from the bag and tested in air. I am in a steady state in the water while taking the reading, not ascending or decending. The longer the dive the closer my VO2 gets to zero. I am diving in water temperatures in the 48-50 degree F range at the moment.

I see no point in having a computer calculate O2 exposure and deco from faulty data. You can't dry a cell with a loop flush on a Drager like I gather you can on at least some CCRs.

So is it my o2 cell or me that is all wet? What are your experiences using a VR3 or Explorer to measure inspired O2?