Processing of Backscattered Signal in Ultrasonic Testing

A method for processing backscattered signals in the ultrasonic testing of thick-walled articles is proposed. The method is based on normalizing the intensity of recorded signal to the energy per one cycle from the moment of signal emission to the first reflected bottom signal. The method allows one to take account of the level of probing signal, the effect of the acoustic contact, the reception-path gain, and the damping of the propagating signal as well as produce the profile of the cross section of backscattering of ultrasound by the material along the signal propagation path. The backscattering cross-section profile provides a basis for identifying scattered damage in the bulk of the material. Results of experimental testing of the method are provided. A technique for determining the minimum gain required for the “correct” reception of backscattered signals has been developed.