Trial manufacturing of isotropic random surfaces for calibration and uncertainty analysis of surface profiling instruments

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Wet-blasting and Wire Electric Discharge Grinding methods are applicable to manufacturing the isotropic random surfaces for calibration of profiling instruments on the market. Quality engineering techniques were applied to obtain the optimized machining conditions by which uniform surface texture can be successfully produced. On the other hand a computer program to generate various sets of discrete topographic data by following the auto-regressive model was accomplished. The common data file format (partly modified SDF) was introduced for both measured surface topographic data and simulation data calculated by a computer. Established was the methodology by which we can divide the measurement uncertainty into the part related to measuring principle including instrument hardware and that caused by software to calculate certain geo-statistical parameters. Some differences in the parameter definitions were disclosed among the software attached to representative commercial instruments. The measurement uncertainty analysis in this research project was limited to the dynamic behavior of sensing devices. It means that the uncertainty component caused mainly by mechanical structure was not taken into account. Commercial and practical surface profiling instruments being based on the optical non-contact method were roughly classified into conventional scanning system by a point-type displacement sensor and areal interferometer system. In the former case, outlier detection and data correction was conducted in the 2D linear system. For the latter case, the similar data pre-processing was utilized in the 3D areal system. The performances of those pre-processing programs were studied through the representative geo-statistical parameters using the manufactured random surfaces. Finally the all-purpose surface topography analyzing software named by "Summit" was completed.