| 摘要 |
PURPOSE:To identify the worked part of the internal surface and cracking of an object to be examined by extracting characteristic parameters, and comparing these parameters with the empirical values having beforhand been obtained. CONSTITUTION:In order to identify the characteristics of reflection bodies F1, F2 existing in an object 1 to be examined, a frequency analyzing circuit 4, a characteristic extraction circuit 5, an output circuit 6 and a data storage circuit 7 are provided other than a contactor 2 and an ultrasonic wave receiver 3. The circuit 4 calculates spectrum intensity q(f) from the prescribed time width tau of the RF signal of an ultrasonic echo (r). The circuit 5 extracts gravity frequency fG and frequency width DELTAf from frequency spectra. The output circuit 6 is a circuit which plots the gravity frequency fG and the frequency width DELTAf at the frequency spectra of the ultrasonic frequency echoes from a certain reflection body F on a two dimensional map. The boundary line identifying the worked part of the internal surface and cracking is beforehand stored as input information Ex in the circuit 7 based on the results of the experiments using known test pieces, and is inputted from said circuit 7 to the output circuit 6. |
