In situ non-contact measurements of polished surfaces

Measurement of 3D surface roughness usually involves removing the part from themachine tool between two operations potentially introducing systematic errors. Furthermore, surfaceroughness measuring instruments are not suited for measuring heavy and large parts such as stampingdies. This paper presents a method to measure the surface topography of a part in situ, i.e. directly on themachinetool without removing the part. After introducing the sensor technology and the data acquisitionchain, the effects of geometric imperfections of the machine tool on the measurement results are discussed. An application of the method is then presented to assess afinishingprocess on a five-axis machine tool.