Uncertainty evaluation of piezoelectric constant measurement based on dynamic resonance method

The piezoelectric strain constant d₃₃ plays a pivotal role in characterizing the energy conversion efficiency of piezoelectric materails. The dynamic resonance method is the reference method to measure the constant. To evaluate the uncertainty, a measurement system based on impedance analyzer iwas set up. A labview programme is written to achieve automatic measurements and data analysis. Based on the mathematical models, the sweeping frequency step was optimized, and the characteristic parameters of piezoelectric ceramic NCE51 cylinders were tested and finally the uncertainty is evaluated. For 15 mm thick samples, the relative expanded uncertainty of d₃₃ measurement of piezoelectric ceramic is 0.96% (k=2), when the frequency step is selected as 50 Hz. Thus the sample measured by dynamic resonance method can be used as reference material to calibrate the commercial d₃₃ measurement apparatus, which uncertainty is about 2% to 5%.