スリット開口による旋削面粗さ(RMS)測定

抄録

In this paper, a new and simple turning-surface root-mean-square-roughness(RMS) measuring method by Fraunhofer diffraction of a slit aperture is investigated. A He-Ne laser parallel beam illuminates a slit aperture formed between a test object and a reference knife edge. The absolute value of RMS is obtained by the zeroth order Fraunhofer diffraction light intensity as a function of the slit aperture width. This measurement method is characterized by non-destructive technique and obtaining the absolute RMS value of a surface profile. The experi-mental error caused by the slit aperture width and the laser beam output fluctuation is discussed by a numerical anlysis of a periodical-surface profile model. Measurements are carried out several turning-surfaces. The typical turning-surface RMS values by employing this method are compared with the calculated values of experimental results using a stylus instrument and the previous surface profile measurement method, and the RMS values of three experimental methods almost agree.