In this paper a new low cost angle generator intended for the calibration of autocollimators
is presented. After describing the working principle of the autocollimator, the calibration
procedure is outlined. It is comparison based where the small angles are derived from
relatively large displacements. Following the presentation of the operation of the
small angle generator, the various error sources are discussed. Finally the paper
gives a summary of the calculation of the extended calibration uncertainty.
