Modeling and Simulation of Pulsed Electroacoustic Measurement Method

Pulsed electroacoustic (PEA) method is a very popular method for measurement of charge in dielectrics. In this method, an acoustic wave proportional to charge is generated by a pulsed HV. The acoustic wave traverses several material layers before being sensed and converted to electrical signal by a piezoelectric transducer. Due to multiple reflections in its path, a direct analysis of traveling acoustic wave would be complex. In this paper, we have proposed simulation of the physical model of the PEA method consisting of electrical and acoustic circuits. Using PSpice model of the method, authors have tried to address some design-related issues, which appear to have not been reported in earlier works. The acoustic circuit has been realized using analogy between acoustic wave and wave propagation in electric transmission line. The piezoelectric transducer is also modeled as a transmission line as in modified Leach's transducer model, except that, in the present case the transducer absorbs acoustic signal instead of generating. Approximate theoretical equations have been used to compare with simulations, wherever a comparison is possible, and found to match well in those cases.