LASER VIBROMETER CALIBRATION AT HIGH FREQUENCIES USING CONVENTIONAL CALIBRATION EQUIPMENT

The calibration of Laser vibrometer is an increasing demand in industry and research. The equipment suggested for use in particular for high frequency calibration, however, is typically of prototype stage and not commercially available. This is due to the demand of the employed homodyne quadrature method for a certain minimum displacement, typically a quarter of a wavelength, of the vibrating object. The authors demonstrate that this is not necessarily a compulsory condition. With conventional, commercially available components it is possible to set-up a system for Laser vibrometer calibration up to 90 kHz. This could be achieved by employing a distinctive optical set-up combined with an unusual (dual frequency) excitation and an improved or extended signal processing.