Inacurrate PPO2

Reefhugger

I have Kiss Classic with my VR3 plumbed into one my O2 sensors. When I calibrate my VR3 in my O2 screen the top line reads 21.0% but the PP line underneath reads .223 and this discrepency continues throughout the dive. I have attempted to write to Delta P with no response. Does anyone have any ideas how to fix this discrepency?

York

Reefhugger,
I may be wrong, but I think this depends on which version of the VR3 you have. If I understand it right, your VR3 takes ambient pressure into account while calibrating. If you calibrate at "normal pressure" in air, both your fO2 and PO2 will be 0.21. However, if you calibrate at increased ambient (higher pressure due to wheather), your PO2 will be higher than your fO2. So the reading of PO2 on your VR3 may actually be the correct one.
If you compare this to your KISS handsets than there will be a discrepancy because you manually calibrate the handset and assume PO2=0.21 when in fact PO2 (not the fO2!) is higher.
The discrepancy should be minimal however, and your PO2-sensor itself only has an accuracy of 0.01. If it bothers you you might want to consider taking ambient pressure into account when calibrating your KISS-handsets.

Hope this helps.

Joerg

Reefhugger

Thanks for the response. However, the pp number is always the same difference regardless of weather, setting or anything else. The problems is that it is also calulating my deco based on that number that is .12 off which is significant. I have 2007 version 3. Plus I have other VR3 users diving with me that do not have the same issue.

Bruce