Quantitative evaluation of powder spray effects on stereovision measurements

Abstract

"The effects of powder spray on surface topography and gauge repeatability and reproducibility (R&R) of a stereovision measurement system are investigated for specular machined components. Results obtained in the micro-scale laser profilometer and macro-scale stereovision measurement of powder sprayed surfaces are correlated. Three artifacts, two step gauges and a gauge ball, all with specular surfaces, are utilized to evaluate this optical, non-contact measurement method. While the use of powder spray has demonstrated the reduction of the measurement noise of the stereovision system, as shown in this study, the surface topography of powder spray is not suitable for um-level precision measurements with the powder droplets as high as 98.4 um. The accuracy and gauge R&R of the system for a 32 um step height are 9.4 and 4.6 um, respectively. A case study of flatness measurement of an automotive engine head combustion deck surface is conducted."