Compressive type accelerometer made by leadfree Bi0.5Na0.5TiO3- based piezoceramics

Compressive type accelerometers are widely used in various vibration measurements. Lead-free piezoelectric ceramics as sensitive element have been preferred from the viewpoint of environmental impact. In this paper, 0.30 wt% MnO-added Bi_0.485Na_0.425K_0.06Ba_0.03TiO₃ (BNKB) piezoelectric ceramics were used as the sensitive element in a compressive type accelerometer. Based on the finite element analysis, the influences of the mass of the preloading element and the thickness of the sensitive piezo-rings on charge sensitivity and operation frequency were analyzed, thus optimizing the structure and parameters of the accelerator. The sensitivity (calibrated by a back-to-back method) of the accelerometer as-fabricated was measured to be 3.9 pC/m·s^-2 within 100 Hz-5 kHz within the 2dB tolerance.