抄録
2-D software datum named as the 2-D mixed method has been constructed to measure mirror surface profiles. The probe of this method consists of two displacement and two angle sensors. Differential calculation of outputs of these four sensors eliminates pitch, roll and the z-directional translation errors of the scanning stages. An autonomous procedure to estimate and compensate the zero-adjustment error among these four sensors is also proposed. By using this software datum, 2-D profiles of ultra-precision surfaces can be measured absolutely without using any external reference. An experimental probe for realizing the 2-D mixed method has been developed and a mirror surface of 128 mm long and 64 mm wide was measured with the probe. Repeatability of measurements and reproducibility compared with the differential angle method have shown high reliability of the proposed method
