Ultrosonic pulse-echo testing is gaining increasing attention for its feasibility, accuracy, and versatility in structural examinations of concrete constructions. A1040 MIRA 3D PRO is an emerging low-frequency pulse-echo ultrasonic tomography device. Developed in 2021, this device is claimed to be suitable for manual and automated concrete structure assessment with the help of its functions, such as 3D-TFM (Total Focusing Method)/FMC (Full Matrix Capture) imaging. However, both its capacity and limitations need to be investigated in more detail. In this thesis, experiments are conducted first on a 2D concrete structure to examine the data acquired when the transducers are working in linear configuration and matrix configuration (array modes). Then, measurements were carried out on a 3D concrete structure to check the 3D properties of the device with the help of the data processing software InterSAFT. The results show a good correspondence between different array modes and that 3D SAFT could visualize 3D structures in an adjacent position. The data recorded at a greater distance was overlaid by noise, which is attributed to the fact that the frequency of the ultrasonic waves was set too high. Finally, further experiments on frequency calibration, data comparison, and measurements on more complicated specimens were suggested for future research on MIRA 3D PRO.