Being a big fan of simplest solution theory, I'm taking someone's theory (don't remember who) that the bar is exactly 7/10 pixels shaded as true, and theorizing the 32 as the bar's current readout. 45 5/7 is then the bar's full reading. I did the math on a lower topic and also found a match...but I'm a bit too lazy to reprint/repost/re-do the math, but from what I've seen of 4 dials at least, there might be a pattern of arithmetic. Dial #2 might seem to support this contention.

'Course I'm probably wrong, but hey...; P