| 摘要 |
PURPOSE:To enhance an S/N ratio by providing a correlation operation part using a transmission signal as a reference signal for calculating the correlation function with a received flaw detection signal. CONSTITUTION:When a synchronous signal is inputted from a synchronous timing generation part TG, positive and negative binary limited code rows having a predetermined sharp autocorrelation function are outputted from a code generator 3 while a T-unit time per one code is held to be inputted to a code waveform generation part 4. Next, in the generation part 4, waveforms having a component of fixed frequency f0 are respectively generated with phases of 0 deg., 180 deg. for the period of the T-unit time in the case of positive and negative codes. Subsequently, the transmission signal from the generation part 4 is amplified by a transmission part 2 and applied to a probe 1 and also stored in a reference waveform memory part 7 as a reference signal. The transmission signal applied to the probe 1 is inputted to a test body and reflected therefrom to be inputted to a correlation device 8 through the probe 1 and a receiving amplifying part 6. The correlational operation of the flaw detection signal outputted from the amplifying part 6 and the reference waveform stored in the memory part 7 is performed in the correlation device 8 and the operation result is displayed on a display part 11. |
