Optical micrometer for radial graduation interval measurement - uses rotatable wedge element for graduation marking image rotation and displacement

摘要

An optical micrometer for measuring the intervals between radial graduations is partic. for use with geodetic angle measurement devices with circular graduations. It enables optical shifting and rotation of the image of a graduation marking to superimpose it on a reading scale. The important optical component is a wedge (13) rotatable about an axis perpendicular to the plane of the circular graduations or an optically conjugate plane and to a refracting edge. The wedge angle depends on the radial graduation marker extensions, the optical rotation required, and the wedge material refractive index.