Hello, If I want to measure the concentricity of a cylinder with another, is it possible using a CMM? If yes, can you pl. explain me the procedure? I have read that concnetricity has to be measured based on the mid point of a diameter-line of a cylinder. This means, I have to measure the co-ordinates of two exact opposite points in the circumference of the cylinder. And then, I have to repeat this for atleast 3 (?) different diameter-lines. How can I do this in CMM without any arrangement to index the job exactly by 180°? I hope I have explained the portion of my confusion here. Kindly help me out! Thanks.