Arrangement for reading the graduated circle on one-second theodolites

摘要

This arrangement contains a graduated circle with numbered graduation in degrees and an optical micrometer for measuring the points on the graduated circle which are diametrically located and brought into coincidence, the optical micrometer consisting of a fixed wedge and two moving wedges, the moving wedges being arranged in such a manner that they are displaceable with respect to one another and with respect to the fixed wedge, one moving wedge being connected to a coarse scale and one moving wedge being connected to a fine scale in such a manner that the graduations of both scales are opposite one another and one graduation line of the coarse scale forms the reading index for the fine scale, a measuring index being provided for setting the coarse scale, and a mask in the plane of measurement of the microscope which limits the coincidence indications of the lines on the graduated circle in such a manner that the intermediate coincidence is masked out. The invention creates an arrangement for reading a graduated circle, in which a digital stepping-down of the degree interval to one 0.1 mgon interval is achieved with the aid of an optical micrometer, with an opto-mechanical digital display, with the aim of achieving a simplified, more accurate and faster reading of the graduated-circle indication.