Piezoelectric Shaker Developments for Calibration of Accelerometers at Extended Frequencies

Piezoelectric shakers are well suited to generate motion suitable for use with laser interferometric methods at frequencies of 3 kHz and above. One advantage of piezoelectric shakers is the higher achievable accelerations and displacement amplitudes as compared to electrodynamic (ED) shakers. Another advantage is the use of a solid ceramic construction rather than a compliant suspension system which results in much lower mechanical noise. Piezoelectric shakers have been developed and used at NIST for many years for high frequency calibration of accelerometers. Previous papers have documented the performance of these shakers for the calibration of accelerometers over the range of 3 kHz to 25 kHz using interferometric calibration methods. Piezoelectric shakers with solid ceramic construction coupled with new high resolution data acquisition systems have made it possible to extend the calibration of accelerometers to smaller amplitudes and a broader range of frequencies. These factors have also allowed calibrations to be performed over a wide range of accelerations rather than over a relatively limited range of accelerations. This paper presents these topics and gives examples of the results of calibrations performed using a piezoelectric shaker and a high resolution data acquisition systems.