ABSTRACT
This chapter presents a few basic principles of transducer design. Manufacturers of piezoelectric or magnetostrictive materials usually make available specific information on the characteristics of their products, which is helpful in designing and fabricating transducers and ultrasonic systems. Ultrasonic energy is generated and detected by devices called transducers. In ultrasonics, the most typical conversions are electrical to ultrasonic energy or ultrasonic to electrical energy. Piezoelectric, magnetostrictive, and electromagnetic transducers are electrical devices; that is, they convert electrical energy to ultrasonic energy or ultrasonic energy to electrical energy. Piezoelectric transducers are used at all ultrasonic frequencies for generating and detecting ultrasonic energy at all levels of intensity. Magnetostrictive transducers are used at the lower ultrasonic frequencies, primarily for generating high-intensity ultrasonic energy. As ultrasonic measurements move into more diverse types of sensing applications, new transduction technologies are being added. Ultrasonic transducers, employing some form of piezoelectric material, are available to operate at frequencies from below 20 kHz to above 2 GHz.
