| 摘要 |
PURPOSE:To calibrate a three-dimensionally-shaped body to be inspected, by a method wherein a spherical reflector is detected in a state wherein theta1 and theta2 axes are fixed and then after the theta2 axis is rotated at an angle of 180 degrees, a tilt angle is calculated from a deviation of coordinates obtained by the two detection, and thereby the rotational origin is corrected. CONSTITUTION:First a theta1 axis 11 and a theta2 axis 12 are adjusted so hat an ultrasonic beam 15 be parallel with any of three axes (x, y, z) intersecting one another perpendicularly. In a state wherein the axes 11 and 12 are fixed, subsequently, the axes (x), (y) and (z) are driven, a ball target 8 is detected by the focus of the beam 15, this state is defined as an attitude I and values of the coordinates at this time are denoted by xI, yI and zI. The axis 12 being rotated at an angle of 180 degrees, then, the target 8 is detected, this state is defined as an attitude II and the values of the coordinates at this time are denoted by xII, yII and zII. Since the direction of fitting of an ultrasonic probe 14 and the direction of the beam 15 are not in a straight line, but tilted, a declination being an angle of deviation of the two directions is calculated and this declination is used as a corrective value and given as an instruction value of a microcomputer. |
