Calculo del ángulo de desviación en un pentaprisma, en función de los errores en los ángulos de 90 y 112.5 grados y el error piramidal

Abstract

An expression is derived showing the relationship between the errors in the 90 and 112.5 degree angles of a pentaprism and the angle formed between entrance and exit beams (angle of deviation). A relationship between the pyramidal errors of each prism surface and the deviation of the exit beam from the plane defined by the entrance and ideal exit beams is also deduced. Finally, a method for constructing a pentaprism with a particular error making use of these derivations is discussed. The fabricated pentaprism is used to characterize a coordinate measuring machine of large dimensions.