Abstract: The curvature of an edge such as the trailing edge of a turbine blade having a specular reflection surface is inspected by illuminating the surface area to be measured with a laser beam and sensing the reflected laser light. The laser beam intensity across the cross-section of the laser beam is varied by a radiation intensity matrix located between the laser beam generator and the edge to be sensed or measured, whereby local radiation intensity variations are provided in the form of illuminating laser beam segments (A, B, C, . . . ) having different intensities. The beam reflected segments (A', B', C', . . . ) have a reflection angle that is equal to the incidence angle of the respective illuminating laser beam segments (A, B, C, . . . ). This fact is used for the correlation (A, A'; B, B'; C, C', . . . ). The reflected beam segments (A', B', C', . . . ) are scanned in a line-by-line fashion whereby the radiation intensity values varying along the curvature are measured.

Abstract: The curvature profile of edges, such as trailing edges of propulsion plant blades or vanes is measured by a device that uses a laser beam for illuminating the curvature profile. The laser beam is generated by a laser that causes its beam to pass through a radiation intensity matrix arranged between the laser and the curvature profile. The radiation intensity matrix has locally different intensity values for varying the laser beam intensity over the cross-section of the laser beam. Sensors are so arranged that they sense the reflection values of the laser beam along the curvature profile of the profile edge. The outputs of the sensors are operatively connected to a central processing unit for ascertaining the curvature profile on the basis of the sensed reflection values. Thus, even sharp edges, such as knife edges, cutting tool edges, or propulsion plant blade edges can be checked for their current quality.