Abstract
To test an air-bearing displacement probe for aspherical surface measurement, measurements at various contact angles are carried out. A laser interferometer is employed as the reference in the measurement. Two methods are also presented to measure the profile error of the probe sphere through scanning a sample sphere. In the first method, two repeated scanning is conducted along the redial direction of the sample sphere before and after a small rotation of the sample sphere. In the second and the sample sphere is scanned while it is rotated by the spindle. The profile error of the sample sphere can be separated by data processing in each of the method.
