Real-time measurement of surface roughness using a device with a laser light source and photo-diode detector coupled to light reflected from an object surface by an objective that allows determination of mean surface brightness

摘要

Device for determining the surface roughness of a component has a coherent light source from which a light beam is directed perpendicularly towards the component surface (5). An objective (7) focuses the light on to the light sensitive surface of an optoelectronic transducer, such as a photo-diode (8). The latter generates an output signal that is proportional to the incident light quantity. Two configurations are possible: the first where light is incident perpendicular to the surface and a beam splitter (4) is used, the second where light is incident at a slight angle to the normal, so that a beam splitter is not required.