Intelligent Piezoceramic Sensor for NDT Applications

The paper presents theoretical and experimental research concerning the manufacture of an intelligent piezoceramic sensor for non-destructive tests (NDT) applications in non-metallic materials. The non-destructive impact-echo method is a suitable technique for the flaw detection in the material structure, based on stress wave propagation. A transient stress pulse is introduced into the sample by an impact shock wave hammer placed on the element surface. This method could be applied for non-metallic materials with rugged and non-homogeneous structures, such as the concrete. The active element of the intelligent piezoceramic sensor for NDT applications is the piezoceramic disc which converts the vibrations into electrical signal, than this is amplified by an amplifier electronic circuit. The radial resonant frequency of the piezoceramic disc is 40.5 kHz, optimum for the ultrasound and low frequency sound vibration propagation into non-metallic materials. In conclusion, an improved device was manufactured, that is an intelligent sensor with piezoceramic disc and amplifier electronic circuit, put together into an aluminium case, in order to decrease the signal losses and obtain a good signal to noise ratio, suitable for applications in non-metallic materials.