Effect of Stylus Position Shiftings to Eccentricity and Roundness Value in Glass Hemisphere Measurements

Abstract

In this research, the testing of the effect of stylus position shifting to eccentricity on hemisphere roundness measurement was done in Research Center for Metrology LIPI (RCM-LIPI). The effect would give the acceptable eccentricity value for center adjustment of hemisphere. Least Square Circle (LSC) data fitting and Gaussian filtering were used in data processing. The result showed that the roundness values were constant until 3.3 µm shifting value with 3.23 µm in eccentricity. However, it started to increase significantly when the eccentricity value reached above that, so it gave an uncertainty contribution to the hemisphere measurement.