Effect of Temperature and Pressure Variations on the Resonant Frequency of Piezoelectric Material

Ultrasound transducers are used in a multitude of applications. A typical ultrasound transducer assembly consists of a piezoelectric layer, one or more matching layers and a backing layer. Dimensions and shape of these structural elements and properties of the used materials (especially those of piezoelectric layer) have a great influence on the resulting properties of the ultrasound transducer. The properties of the material used for the piezoelectric layer have strong dependence on the field conditions like temperature and pressure. The paper aims at studying the effect of temperature and pressure on the resonant frequency of the piezoelectric element. The change in the resonant frequency results in change in the material constants of the piezoelectric disc. Using these practical values of material constants, a realistic model of piezoelectric element can be developed. This helps in prediction of behaviour of the resulting ultrasound transducer and accelerates the design procedure. The real-life application considered for the conditions of temperature and pressure is open channel flow measurement. Traditionally used lead zirconate titanate (PL I)-based ceramic is the material chosen for the piezoelectric layer.