Pyroelectricity - A new Application for the Piezoelectric Bulk Transducer

摘要

This report presents a new experimental technique based on an alternative use ofthe piezoelectric bulk transducer used at IMFUFA/NSM, RUC. The measurementsrely on the pyroelectric effect of the piezoceramic material that compose the sphericalhollow transducer shell. In order to explain and analyze the experimental test results,an analytic model is proposed as a solution to the thermo-electro-mechanicaldifferential equations describing the phenomena in the transducer and what fills thecavity inside.Measurements involving the highly viscous 5-PPE / Santovac 5 liquid are conductedin the temperature range from 248 K to 260 K near the supposed glass transitionof the liquid, during which a drastic change in the physical thermodynamicvariables is documented for the liquid.The practical test measurements and the theoretical thermo-electro-mechanical equationsare compared for a discussion of the potential of the experimental techniqueand possible improvements before its application in experimental glass physics areproposed; it is concluded that the technique may be an excellent method for measuringthe isobaric thermal expansivity, ®p, but at present it needs complementingexperiments to decrease the number of independent variables.The report is written in English.