[ls1ac]

You were first asking about the accuracy of the readings, right? Your charts show a normal increase with RPM. I am assuming that you are worried about tracking the car. The exact pressure is not important but rather if abnormal changes take place while driving. I think you maybe over thinking.
To push the way back machine Butten: we used to put tape on the glass to cover about one quarter of end of the needle on the oil pressure gauge in the range that was normal. The gauge was also turned so the normal reading was strait up.When the gauge got outside normal the full needle would be seen and the drivers attention would be drawn to the gauges. The gauges were mechanical with a P-tube so the needle moved a lot. (To day the gauges often have over/under warning lights that will often flicker at idle.)




Edit: In you last post you asked about the loss in a sweeper, check other posts about the many ways to combat that problem.