No description available.

This diploma thesis deals with the theoretical description of interference methods used to measure vibrations, examines main parasitic effects and analyses its contribution to achievable the resolution. In the practical part, it uses several measurements to verify the effects of the level of reflected beam, stand-off distance and speckle noise. It also proposes a practical experiment for measuring dynamic parameters and signal-noise ratio. Results show that, the noise is exponentially dependent on the level of the reflected beam. The visible maximum of the vibrometer proved to be critical in terms of time stability of the measured signal level in two of the three measurements. Results of the dynamic measurement show that, the measured deviations were not degraded or significantly disturbed by the noise signal. From the measurement of the speckle noise, it emerged that the lowest level of noise is achieved with smooth and highly reflective materials.