| 摘要 |
PURPOSE:To obtain high accuracy of measurement without limitation of a magnification, variance owing to an individual difference, etc. by bringing a reference gauge having a knife edge- shaped straight edge into opposite contact with the outside surface of an object to be measured, scanning spot light to the opposite contact part thereof so as to transmit said part, detecting and outputting the prescribed higher harmonic component with a lock-in amplifier and recording and reading the same. CONSTITUTION:The straight edge 2a of a reference gauge 2 of which the bottom end edge is made into a knife edge-shaped straight edge 2a is brought into opposite contact with the crowned outside surface 1a of a cylindrical roller 1 which is an object to be measured in the position where the edge 2 is parallel to the axis of the roller 1. The entire region in the axial direction (X-axis) of the roller 1 in the opposite contact part is scanned in the opposite contact direction (Z-axis) intersecting orthogonally with the X-axis by the spot light projected from the direction intersecting orthogonally with both X- and Z-axes. The light transmitted through the opposite contact part by such optical scanning is condensed by a photodetecting part 3 consisting of condenser lenses 3a, 3b and is made incident to a photomultiplier tube 4, by which the light is photoelectrically converted and the electrical signal corresponding to the intensity of the transmitted light is obtd. The gap width DELTAZ in the actual opposite contact part corresponding to the scanning position is calculated in accordance with the relation held between said electrical signal and the width DELTAZ in the opposite contact part, by which the crowning shape is measured. |
