Which type of ultrasonic testing method is commonly used for measuring thickness?

The pulsed echo method is widely recognized for measuring thickness in materials. This technique involves sending an ultrasonic pulse into the material and measuring the time it takes for the reflected echo to return after bouncing off the back surface. By knowing the speed of sound in the material, the thickness can be accurately calculated based on the time-of-flight measurement.

This method is particularly effective because it allows for the detection of changes in thickness due to corrosion, erosion, or other forms of wear without needing to disrupt the material itself. The pulsed echo technique is also commonly used because it can provide real-time measurements and results, which are essential in many industrial applications.

In contrast, other methods like through-transmission, ultrasonic imaging, and acoustic emission are not primarily focused on thickness measurement. Through-transmission typically involves sending sound waves through a material and measuring the signal on the opposite side, which is more suited for evaluating defects rather than measuring thickness directly. Ultrasonic imaging creates visual representations using multiple echoes, while acoustic emission techniques are used for monitoring dynamic events rather than measuring static properties like thickness.