Admittance Measurement and Equivalent Circuits for Piezoceramics Using a Virtual Analyzer

The impedance or admittance characteristics of piezoceramics must be recognized by a spectrum analyzer to gain the electromechanical match at resonant frequencies before piezoceramic actuating applications. A virtual analyzer has been developed using an integration technique with a data acquisition card and software Lab VIEW tools. According to the five different mathematical models of equivalent circuits, the most suitable model has been identified to demonstrate the electromechanical feature of piezoceramics. The voltage is inputted onto the piezoceramics and the current sampling simultaneously. Thus, instantaneous admittance levels relative to frequencies are furnished in the functional panel of the virtual analyzer. The measured results from the virtual analyzer and the actual data through a HP-4194A analyzer are compared to validate the performance of the virtual instrument.