Profile Measurement with No Standard

Verification Experiment for Profile Measurement along a Circle

Abstract

A verification of a measurement method of surface profile along a circle with no standard is carried out. For the measurement, spacings between two unknown surfaces located almost in parallel are measured along a circle. One of the surfaces is rotated around the center of the circle and the spacings are measured again. This procedure is repeated many times. From these data, the profiles of two surfaces are calculated with a system of simultaneous linear equations. For the purpose of a verification experiment, a simple surface measuring apparatus is constructed which has 12 electric comparators arranged along a circle. Their zero point positions correspond to one of two surfaces. A random inclination and a random displacement can be given intensionally to the surface to be measured. The surface profiles obtained by different experiments agree well with each other and with the profiles obtained with a 3-dimensional measuring machine.