Absolute interferometric torus testing method

摘要

The test method involves placing the object in a toroidal beam path of an interferometer test beam for a first measurement and rotating it by one evaluation raster increment for a second measurement. A mirror replaces the object for a third measurement. A plane mirror arrangement, which contains an odd number of plane mirrors, is positioned with respect to the object for a fourth measurement in which the mirror image of the object is located in the position occupied by the object during the first measurement. The absolute deviation and interferometer error are determined by computerised combination of the measurement values.