Phase shift characteristics of commercially available vibration and acceleration pick-ups

摘要

Phase shift evaluation of pick-up has become important in recent vibration and acceleration pick-up applications, such as modal analysis, active control of vibration isolation, and inertial navigation. However, manufacturers have not quantitatively reported frequency-phase characteristics of the pick-up in the past. This report presents the results of phase shift evaluations of three types of commercially available vibration and acceleration pick-ups (piezoelectric type, servo type and capacitance type). The evaluations were performed using the sine-approximation method, which will be adopted in the updated ISO standards. The phase shift and the uncertainty of each pick-up have been elucidated. Expanded uncertainties of less than +- 6 x 10~(-3) rad in phase shift evaluation at 5 kHz have been obtained. Three piezoelectric-type ipck-ups from different manufacturers have also been evaluated and compared. We observed a phase shift difference of up to 4 X 10~(-2) rad in each sensor.