Distance perpendicularity (Z axis) from cilinder core to plane

[[Re...]]

I am not able to measure distance in one direction.

The distance is not perpendiculare.  

[[Jo...]]

Why do you think it is not perpendicular?

Edited August 21

[[Ma...]]

Once you use projected distance, then use just "L" - using "L" with axis will result in measuring distance depending on active/selected alignment.

[[Jo...]]

If in doubt you can test perpendicularity by constructing a projected line with the same point and zylinder and then check the angles to the zylinder axis.