Measurement of surfaces, especially spherical and aspherical surfaces, involves sensing surface in polar co-ordinate system so that sensor is always perpendicular to best fit sphere

摘要

The method involves contactless or contact sensing with sensor whose signals are evaluated. The surface (8) is sensed in a polar co-ordinate system so that the sensor (3) is always perpendicular to the spherical surface nearest to the aspherical surface (best fit sphere). The surface and sensor are rotated about axes that intersect at the centre of curvature of the best fit sphere at an adjustable angle. An Independent claim is also included for an arrangement for measuring surfaces.