Abstract
Although the resonant ultrasound spectroscopy (RUS) is useful for efficient testing of surface and inside of objects, the resonance property (resonance frequency and mode amplitudes) is influenced by the boundary conditions of supports. To eliminate this influence, we propose a floating resonance method where the resonance property is evaluated after floating the objects, using the non-contact measurement by laser ultrasonics. In a preliminary application to bearing balls, we succeeded to float a 8 mm diameter steel bearing ball by controlled air flow and to improve the reproducibility of resonance frequency to better than 0.005 %.
