Evaluation of a scanning Hartmann device for single point turning applications

This paper concerns a new, machine mounted aspheric metrology device designed to measure a broad range of figures without the use of auxiliary optics. A prototype device, based on the classical Hartmann test, called a Hartmann Optical Surface Tester (HOST) was evaluated on a single point diamond turning machine. Design, initial testing, and validation data from reference spheres, and two types of aspheres are discussed. Results of a simulation model for estimating acceptable alignment errors for the HOST on the diamond turning machine also are presented. Peak-to-valley measurement uncertainty on the test optics was found to be better than 0.08 micrometers .