I am leaning towards this theory too. Especially since I have seen for sure a report where the baseline seems to start near 10 for the one user I posted using the high pressures and M series machine.jedimark wrote: I'm starting to think my original subtracted mean theory isn't far off then. I'll let you all know if I manage to work out for sure which method they used.
I suspect that Doug's original question probably had his showing graph at near the 20 line. Mine just happens to start at zero line.
So at least we now know that not everyone has a zero starting point when reporting unintentional leak.