Question regarding helix path on a cyclinder

[[Ra...]]

I have a simple rod that was was spacing out and taking circles uniformly over the length and displaying the dia.

If i use a helix path , that will save me time and effort. To display the diameter im using the diameter characteristic. Will this take a average ,min or max value ?

How can i then determine if a area is out of spec, where that area is on the rod.

Thank you.