In this paper, VTT MIKES interferometric 2-directional small angle generator (I2D-SAG) with updated model for calibration of autocollimators is described. It generates angles around 2 orthogonal axes with high accuracy. The maximum range of the I2D-SAG is ±1000” for both axes. In calibration of a high quality autocollimator a standard uncertainty below 0.01” can be reached.
In addition, preliminary results of a comparison of I2D-SAG and PTB Spatial Angle Autocollimator Calibrator (SAAC) instrument are presented. This is the first comparison between 2D autocollimator calibration systems. In this comparison, a good agreement was reached in characterization of an electronic autocollimator over 900”×900” range.