| 摘要 |
PROBLEM TO BE SOLVED: To eliminate dispersion of measurement periods of hole positions and to improve a working efficiency by determining a measurement starting angle of a first hole according to a disposing state of an object and alignment of a hole of the object in measuring a hole position. SOLUTION: There are three holes 2 on a band-like circumference on an object 1, the position 3 of the center of gravity of three holes 2 exist at an angleθM from the X-axis of an image data, and linear window group 4 is aligned in unit 1 deg.. The window group 4 is used to provide projection data in the meridian direction, and starts at an angleθS from the X-axis. A corrective angleθH is previously determined for the object 1, the starting angleθS can be calculated based on the angleθM of the position 3 of the center of gravity. The corrective angleθH is corrected according to a state in which the holes 2 are collected on the top surface of the object 1, and is experiencedly set by observing an alignment of the plurality of holes 2. This does not require measurement beyond 360 deg., can make a measurement smaller than 360 deg. according to the alignment of the holes 2, and therefore, allows reduction of a measurement period.
|
