A comparison of sensitivity standards in form metrology: Final results of the EURAMET project 649

Results of an intercomparison measurement of sensitivity standards are presented. The standards circulated were a flick and two multi-wave standards (MWS). The measurands were form deviation and, for the MWS only, the height of the dominant spectral components. For the flick, influences from mechanical filtering and calibration are discussed. For the MWS several influencing quantities are identified and discussed. Some of these influencing quantities may dominate the result under certain circumstances. It can be shown that standard measurement uncertainties of smaller than 25 nm can be achieved for the amplitude heights of MWS, whereas the form deviation results disagree a little more than expected compared to standard uncertainties of the order of 50 nm.