A novel piezo vibration platform for probe dynamic performance calibration

A novel piezo vibration platform of compact size (120 x 120 x 120 mm(3)) fo r probe dynamic performance calibration has been developed. A piezo tube is employed to generate movement which is measured in real time by a miniatur e fibre interferometer and close-loop controlled by a fast digital signal p rocessor, thus the calibration can be made traceable to the national length standard. 20 kHz control-loop frequency with 1.71 mm uncertainty has been achieved. The maximum calibration range is 20 mum with 0.3 nm resolution. T he piezo vibration platform can generate up to 300 Hz sinusoidal signal and various other waveforms, such as square, triangle and saw tooth. It can al so work in sweep mode to shift the frequency up to 100 Hz continuously, whi ch is a very useful function when the amplitude-frequency response of the p robe is to be investigated.