Influence of material dispersion on the measurement accuracy of chromatic sensors

Abstract

The work deals with the problem of non-contact measurement of the surface topography using chromatic (confocal) sensor. A detailed analysis of the influence of the refractive index of the plan-parallel plate material on the accuracy of measurement using chromatic sensor is performed. Relations which describe this phenomenon and enable to calculate an error due to material dispersion are derived. It can be seen from the performed analysis that the dispersion of plan parallel plate material causes measurement error that cannot by neglected for precise measurements.