光学式内径測定装置を用いた四角形穴測定精度の理論的解析

抄録

In this paper, the error in the measurement of a gap larger than 0.3mm inside a quadrilateral hole, using an optical noncontact measuring equipment, is discussed theoretically. The experimental results show that the measurement error of the gap varies with the gap length of the specimen. It is verified in this paper that the cause can be analyzed by taking into account the spherical aberrations of the lenses in the measuring equipment. The maximum spherical aberration of the lenses was 50μm. The maximum measurement error of the gap is denoted by e. The calculated results show that e is +1.0μm in a 0.3mm×0.3mm square hole, e is -0.30-0.35μm in a quadrilateral hole with a gap larger than 0.6mm when the spherical aberration is taken account and e is always negative when the spherical aberration is assumed to be 0.