Backwall echo
Back wall echo is the ultrasonic echo reflected from the workpiece back wall opposite the test surface. It serves as a reference signal for wall thickness measurement and detection of sound attenuation.
Physicochemical Mechanism of Action
The backwall echo forms when the ultrasonic pulse is reflected at the back wall of the component. This echo serves to determine the wall thickness and to detect possible sound attenuation.
Metallurgical Relevance & Welding Risks
Wrongly interpreted backwall echoes can cause faulty measurements and hurt the accuracy of the wall thickness measurement. This can lead to inaccurate material checks and potential safety risks.
Workshop Practice & Instructions
To interpret backwall echoes correctly, the ultrasonic test must be carried out with the right frequency. The test surface should be clean and free of contamination. The measurement should always be repeated under the same conditions to get consistent results.