Rapid surface roughness testing method and instrument

Surface roughness presents microsurface topographic variances and irregularities; it is an important characteristic in many experiments and model construction. A quick testing method and an instrument for surface roughness measurement were developed in this study. A laser was emitted onto the test subject, the reflected light was directed to the camera and the images were then captured through a linear scanning process. The three-dimensional (3D) coordinates of the measurement area were then obtained after image processing and coordinate transformation, and multiple surface roughness levels were calculated by employing the 3D coordinates. The precision experiment and field experiment showed that the instrument has a maximum average comparative error of 2·93%, and the instrument was able to replicate the 3D structure of the test subjects precisely. A series of surface roughness parameters was calculated as the final measurements. The instrument and the controlling/postprocessing software are available by contacting the authors.