Utensil for evaluating length measurement error in x-ray ct device for three-dimensional shape measurement

A utensil for evaluating a length measurement error in an X-ray CT device for three-dimensional shape measurement, which utensil is positioned for use on a rotation stage of the X-ray CT device for three-dimensional shape measurement such that a Z axis as a rotation axis of the rotation stage coincides with a center of a cylindrical imaging space, the utensil comprising:

• a base;
• and
• multiple spheres arranged in an XYZ space on the base corresponding to the imaging space, wherein:
• the multiple spheres include multiple outer circumference side spheres arranged on one outer circumferential circle around the Z axis in each of multiple X-Y planes having different Z positions;
• a radius of an outer circumferential circle on which the multiple outer circumference side spheres are arranged in each of the multiple X-Y planes is same and coordinates (X, Y) of multiple outer circumference side spheres arranged in all of the multiple X-Y planes are different;
• and
• the multiple outer circumference side spheres include two sets of two spheres symmetrically arranged with respect to the Z axis.

A utensil for evaluating a length measurement error in an X-ray CT device for three-dimensional shape measurement, which utensil is positioned for use on a rotation stage of the X-ray CT device for three-dimensional shape measurement such that a Z axis as a rotation axis of the rotation stage coincides with a center of a cylindrical imaging space, the utensil comprising:

• a base;
• and
• multiple spheres arranged in an XYZ space on the base corresponding to the imaging space, wherein:
• the multiple spheres include an outer circumference side sphere arranged on one outer circumferential circle around the Z axis in each of multiple X-Y planes having different Z positions;
• a radius of an outer circumferential circle on which the outer circumference side sphere is arranged in each of the multiple X-Y planes is same and coordinates (X, Y) of an outer circumference side sphere arranged in all of the multiple X-Y planes are different;
• and
• multiple outer circumference side spheres are arranged in each X-Y plane such that a projection position on a reference X-Y plane whose z-coordinate is zero is put at regular intervals along one circle around the Z axis.

A utensil for evaluating a length measurement error in an X-ray CT device for three-dimensional shape measurement, which utensil is positioned for use on a rotation stage of the X-ray CT device for three-dimensional shape measurement such that a Z axis as a rotation axis of the rotation stage coincides with a center of a cylindrical imaging space, the utensil comprising:

• a base;
• and
• multiple spheres arranged in an XYZ space on the base corresponding to the imaging space, wherein:
• the multiple spheres include multiple outer circumference side spheres arranged on one outer circumferential circle around the Z axis in each of multiple X-Y planes having different Z positions;
• a radius of an outer circumferential circle on which the multiple outer circumference side spheres are arranged in each of the multiple X-Y planes is same and coordinates (X, Y) of multiple outer circumference side spheres arranged in all of the multiple X-Y planes are different;
• and
• multiple outer circumference side spheres are arranged in each X-Y plane such that a projection position on a reference X-Y plane whose z-coordinate is zero is put at regular intervals along one circle around the Z axis.