DYNAMIC PROBE CALIBRATION IN THE MU-M REGION WITH NANOMETRIC ACCURACY

This paper describes a system that enables a traceable dynamic calibra tion of probes of roughness testers and roundness testers, for example . The system is based on a digital piezo translator (DPT). For the cal ibration of the DPT itself, an interferometric technique was used. Aft er calibration by laser interferometry, the DPT is used as a transfer standard that can be driven by signals of various, but exactly known, form. This time-displacement form can range from square to sinusoidal or quasi-random with a maximum displacement of 15 mu m and a maximum f requency of about 300 Hz. From a practical calibration of a roughness tester, it is shown that, depending upon the profile, roughness parame ters can be measured with an uncertainty ranging from a few nm to 1%. (C) Elsevier Science Inc., 1996