Mark,

Above is one of the PO2 traces (green curve) from your dive report.

And below is one of the dives we did on the Repulse (i.e. similiar depth)

I chose this particular dive since we fluctuated the depth quite a bit swimming from the bow to stern to look at the props, then recovered a lost anchor (from another dive boat, not artifact from Repulse) on the swim back.

Despite the depth fluctuation, the Shearwater controller maintained a pretty steady SP (i.e. 1.3) throughout the entire dive.

Bruce uses his proprietary injection algorithm that is supposed to keep the SP very steady. I do like it for the bottom portion where I am working more, but not as much for the ascent or deco phases, just IMHO...

I don't have any traces of my loop PO2 when I was diving the KISS units, but I don't believe mine was fluctuating as much as yours has (i.e. 0.5 PO2 nominally) even at constant depth.

Thus, you might need to check the flow rate on your orifice as it could be too slow and you failed to monitor and add O2 as often as you should (?)


.