SIZE MEASURING METHOD AND DEVICE THEREOF

PROBLEM TO BE SOLVED: To provide a size measuring method and its device capable of simply performing measurement in simple device configuration. SOLUTION: At first, prescribed size data mounts a known master on a reference base 26 and its height is measured. The end face of the master is imaged by a CCD camera 34, and the imaged scale factor of an image projected on CCD is found. The position of the inside diameter center of the master projected on CCD is found. The position of the outside diameter center of the master on CCD is found, and set on a coordinate center. A work is mounted on the reference table 26, and its height is measured. A difference between the height of the master and the height of the work is found, the end face of the work finding the center deviation amount of the work is imaged by the CCD camera 34, and the position of the inside diameter center of the work on CCD is found. The position of the outside diameter center of the work on CCD is found on the basis of the center deviation amount and the position of the coordinate center. The eccentric amount of the inside and outside diameters of the work is found on the basis of the found position of the outside diameter center and the position of the inside diameter center.