ABSTRACT
Piezoelectric materials are well suited for use as the basis of a range of force transducers for both static and dynamic measurements and form the active element in miniature accelerometers, typical configurations. Ultrasonics provides a means for the non-invasive measurement of the flow of liquids in pipes. The transducers used for the generation of ultrasonic frequencies usually work in the reverse sense and can be used as receivers for ultrasonic frequencies. A variety of methods are available operating on very different principles, and the appropriate arrangement must be chosen for a particular application. Surface acoustic wave transducers are available for the measurement of voltage, pressure, force and temperature. These use self-oscillating Surface acoustic wave structures whose frequency of oscillation is changed by the presence of the appropriate external influence. Piezoelectric ceramics are increasingly being used as actuators to provide precise linear displacements of the order of 1 µm with accuracies approaching 10 nm.
