Laser interferometric measurement of building vibrations from anti vibration tables

Abstract

We measured very weak vibrations (less than 1µm amplitude) of the walls of our laser laboratory from indoor by an LDV (Laser Doppler Vibrometer) laser interferometer placed onto passive anti-vibration tables containing compressed air springs. Around their resonance frequencies the tables, however, do not decrease but increase the vibrations of their surroundings, distorting hereby the building vibration measurements. In the paper we describe a method, by which the measured frequency spectra can be corrected, and can be transformed to the resonance free case.