BASIC PROBLEMS AND HOW TO SOLVE THEM
Your task seems to be easy, the solution obvious?
But there may be more than one way to skin a cat ...
There are some typical solutions for simple problems like measuring thickness or diameter. Still, you may be in for a surprise, e.g. the object you want to measure the thickness of doesn't move exactly perpendicular to the measuring beams and seems to be thicker than the manual micrometer tells you.
So check the different settings and take care of the necessary general requirements.