Abstract
We are studying about construction of system of making to visible of internal defect. As the former stage, we developed the device that was able to exchange various ultrasonic probe and to measure high sampling frequency. As the checking operation of the device, we measured the wave reflected at the top of the sample and the bottom of the water tank. As the result, we confirmed precision of the device because the result of the calculation was corresponding to the height of the sample. However, because the influence of the white noise with the amplifier was large, the signal processing was necessary.
