Considerations for the evaluation of measurement uncertainty in interferometric gauge block calibration applying methods of phase step interferometry

Abstract

The approach to evaluation of measurement uncertainty for influences impacting the evaluation of the fringe fraction using digital methods is presented. We also included uncertainty considerations regarding correction for platen flexing in long gauge block calibrations, where the phase of the platen reference surface is extrapolated to the side edge of the gauge block. Contributions to the uncertainty budget for a refractometer cell in the interferometer set-up for long gauge block calibration are outlined, including the effect of correlation between uncertainties in the wavefront phase used in refractivity and central length measurements.