Thickness Measurement of a Curved Multilayered Polymer System by Using an Ultrasonic Pulse-Echo Method

The effect of the curvature on the measurement of thickness of each layer of curved multilayered polymer by using an ultrasonic pulse-echo method was investigated. The real location of the focus of an acoustic beam in a curved, layered structure was calculated by an optical-ray model. Experimental results with the use of ultrasonic pulse-echo measurement systems are presented. The optimization of the focal distance is discussed.