A new method for determining the dynamic behavior of accelerometers by shock excitation and laser interferometry is presented. The method allows the shock sensitivity and the magnitude and phase lag of the complex sensitivity of accelerometers to be measured with high accuracy. After digitizing of the phase-modulated signals at the output of a homodyne or heterodyne interferometer, the time-dependent displacement is reconstructed on the basis of the principle of coherent demodulation. The data processing steps proposed for determining peak value and spectrum of the acceleration signal can be adapted to typical shock pulse shapes. They efficiently suppress deterministic and stochastic disturbing quantities. Computer simulations and experimental investigations also proved that the peak value and the spectral components of shock-shaped accelerations ca be measured with expanded uncertainties of less than 0.2 percent. The method presented and investigated in this paper is widely used to evaluate the linearity of accelerometers within the specified dynamic range and to calibrate precision-grade accelerometers in absolute terms.

Date Published: 1 June 1998
PDF: 12 pages
Proc. SPIE 3411, Third International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, (1 June 1998); doi: 10.1117/12.307704

Published in SPIE Proceedings Vol. 3411:
Third International Conference on Vibration Measurements by Laser Techniques: Advances and Applications
Enrico Primo Tomasini, Editor(s)