| 摘要 |
PROBLEM TO BE SOLVED: To measure a wall thickness of a cylindrical object by acquiring an attenuation profile from the digital image of radiant image of a cylindrical part, and deciding the position of outside surface and inside surface of the wall from a density profile while the wall thickness is decided as an interval between the outside-surface and inside-surface positions of the wall. SOLUTION: A cylindrical object 1 is irradiated with an X-ray or γ-ray 2 of an appropriate energy. An intensity profile P is acquired as a function of measurement position from a radiant picture image projected on a detector of flat, linear, or dot/scan type. This is acquired from an electronic or photon counter value through analogue/digital conversion, digitizing of optical scanner means, or scanning of picture film and fluorescent screen for optical stimulation. The intensity profile P is acquired from the change in wall thickness PW as a function of a lateral irradiation position Y. The corresponding points are shown as S1-S4 in the intensity profile P, and the wall thickness on left side or right side is decided from a distance S2-S1 or S4-S3 along the Y-axis. |
