An ultrasonic thickness testing gauge is used to measure the thickness of materials. Ultrasonic thickness testing equipment consists of a small ultrasonic transducer, a handheld control unit, and surface couplant, as shown in Figure 1. Ultrasonic thickness testing is a stress-wave technique in that it propagates an ultrasonic wave through the material and measures the two-way travel time of the wave. Ultrasonic thickness testing is most commonly used for two applications. The first is to determine the cross section properties of unknown sections. The second is to monitor the section loss of corroded metal structures.
Figure 1: Ultrasonic Thickness Testing Equipment