How to verify the pitch #of nuts?

I've made routines where I run an array of hits along the edge of the threads (as described above), then I parsed out the first Min PR (avoiding lead threads), and aligned Z to that min value.  Voila. As long as pitch is consistent, which you can also extract from that sample array... you will hit along the Min diameter of the threads.

What exactly do you do to parse out your min PR from the array of hits? I've been wondering how other people go about calculating PR, since there isn't an expression command that can pull out PR of a hit.

I am using metric, for pitch 1.5, the distance is 1.5 mm, let us check by every 0.3 mm with diameter 2mm probe,  1-cos( sin-1(0.3)=1-cos(17.5 degree)=0.046 mm.

If check by 0.15mm each( 10 checks), I believe the variation could be below 0.025mm ( This is the MAX, normal should be only half of that). Then pick up the smallest number, adjust the DEPTH.  

pitch should equal the helix ... only for location

Concentricity of threads to -A- - PC-DMIS for CMMs - PC-DMIS - Nexus Community (hexagon.com)

this might help (lazy response i know.  Sorry, i'm super busy this week).