Abstract: A method and apparatus for generating small angles for calibrating autocomators or the like is described. It includes a small angle wedge which is rigidly attached to a mechanical beam which is rotatable about a pivot point. The rotation of wedge causes a very small deviation in the line of sight of an autocollimator under test after passing through the wedge and thus gives a large optical advantage.

Abstract: A small angle generating apparatus is described for deviating optical beams y accurately measurable small angles to calibrate autocollimators or the like. It includes a double mirror combination which is mounted on an elongated mechanical beam which is rotatable about a pivot at one end of the beam by means of a micrometer coupled at the opposite end thereof. Rotation of the double mirror combination deviates a beam of light from a test autocollimator from its original position either horizontally or vertically through a small angle which is linearly proportional to the angular rotation of the mechanical beam.