| 摘要 |
1. Process for the determination of the roughness of a surface (10) without making contact therewith, of the type which comprises, in known manner, irradiation of said surface (10) by means of a beam (4) of laser light (5), determination of the illuminances E1 of that part of the light (9, 11) that undergoes a specular reflection on said surface (10), and E2 of that part of the light (15, 16) that undergoes diffracted reflection by the same surface (10), determination of the ratio E1 /E2 , and determination of the roughness Ra of the surface (10) by comparison with a standard calibration curve, characterized in that the diffracted illuminance E2 is measured by integration of the light received over an annular ring (17) centred on the direction of specular reflection, and guided by a light guide (18) in the form of an annular cone whose base is said annular ring (17) and whose axis is said direction. |
