Pulse-echo is an ultrasonic non-destructive testing (NDT) technique using ultrasonic pulsed waves to find defects in materials. Ultrasonic waves are mechanical vibrations and have a frequency greater than 20,000 Hz. There are two methods of receiving ultrasonic waveforms: reflection and attenuation. In reflection or pulse-echo mode, a transducer performs both the sending and the receiving of the pulsed waves as the “sound” is reflected back to the device. Reflected ultrasound comes from an interface, such as the back wall of the object or from an imperfection within the object. A flaw detection system shows these results in the form of a signal with an amplitude representing the intensity of the reflection and the distance, representing the arrival time of the reflection.