Ultrasonic pulse echo method (UPE) is widely used in the detection of concrete components. It has been proved to be very useful in determining the thickness of concrete components with only one test surface, detecting defects (such as voids, honeycomb and delamination), and verifying the location of grouting defects in pipes.

Ultrasonic pulse echo

Ultrasonic pulse echo is a non-destructive testing (NDT) method used to scan targets in concrete components. UPE method uses acoustic stress waves to study the characteristics of the structure and locate defects by identifying acoustic impedance anomalies different from concrete. This test method is designed to solve the practical limitations of the general ultrasonic pulse velocity tester, such as the need to contact both sides of the concrete element. Although traditional ultrasonic pulse-echo instruments can provide A-scan and B-scan, modern ultrasonic pulse-echo tomography equipment can provide real-time B-scan, enabling engineers to see the targets in concrete more clearly. Mobile applications, artificial intelligence and modern signal processing technology have brought excellent test speed, clarity and 3D view of structure, and are easy to use, Typical equipment include A1040MIRA ultrasonic tomography scanner of ACS in Germany and PD8050 ultrasonic tomography instrument of Proceq in Switzerland.

How does ultrasonic pulse echo work?

As we discussed earlier, the principle concept behind ultrasonic pulse echo test is to measure the propagation time of ultrasonic wave in concrete. Modern ultrasonic pulse-echo instrument consists of a group of piezoelectric transducers, which can be excited to the concrete surface by short pulse, high amplitude pulse, high voltage and high current. When the pulse propagates in the concrete, it will reflect and refract at the interface of voids or other internal targets. Any abnormality in acoustic impedance will cause the emitted pulse and reflected ultrasonic wave to be received at the receiving transducer. Analyze the signal and calculate the wave propagation time, and perform tomography according to the transmission time or velocity. This technology can also be used to indirectly detect the existence of internal defects, such as cracks, voids, delamination or horizontal cracks or other damages.