1. n. [Formation Evaluation]

A device for transforming electrical energy into sound, or vice versa. In sonic logging applications, acoustic transducers are usually made of piezoelectric ceramic or magnetostrictive materials, and may be used as either receivers or transmitters in a frequency range between about 1 and 30 kHz. The transducers are excited as either monopoles, emitting or receiving sound in all directions, or dipoles, emitting or receiving in one plane. In ultrasonic logging applications, acoustic transducers are made of piezoelectric ceramic materials, and often are used in alternating transmitter/receiver (pulse-echo) mode, in a frequency range from a few hundred kilohertz to a few megahertz.

See: monopole,  sonic log,  sonic measurement,  ultrasonic measurement