Preparatory Notes for ASNT NDT Level III Examination - Ultrasonic Testing, UT

Fig. 5.10: Basic design of a single
transducer Ultrasound head
Piezoelectric materials have two nice
properties:
1. Piezoelectric materials change their
shape upon the application of an
electric field as the orientation of the
dipoles changes.
2. Conversely, if a mechanical forces
is applied to the crystal a the
electric field is changed producing a
small voltage signal.
The piezoelectric crystals thus function
as the transmitter as well as the
receiver!