An Impact Technique for Wide Band Characterization of Piezoelectric Accelerometers

In this paper, we propose a novel approach to characterize the response of the piezoelectric accelerometers in a wide frequency range. The method consists in exciting the sensor by a pulse produced by the impact of a high-stiffness and small-mass sphere. First, we give some physical grounds on the impact phenomenon. Then, we propose a simple experimental set-up, and suggest how to tune it at its best. We emphasize the convenience of conditioning the sensors by a differential charge amplifier if this is feasible. Finally, we apply the impact-method to two commercial sensors. As a result, we managed to characterize one of them in a bandwidth up to 250 kHz, detecting up to three resonance frequencies. We discuss the advantages of this technique in comparison with the standard calibration methods.