| 摘要 |
PROBLEM TO BE SOLVED: To provide a crack detector capable of detecting the position of the crack developed in a material to be tested without being affected by noise. SOLUTION: A crack detector is constituted of a pair of AE detection means 5X, 5Y detecting AE waves generated from a material W to be tested, a cross- correlation processing circuit 6 subjecting the signals from the AE detection means 5X, 5Y to cross-correlation processing to calculate correlation characteristics and a crack position measuring means 7 detecting the developed position of the crack of the material W to be tested on the basis of the correlation characteristics from the cross-correlation processing circuit 6. The operation of cross-correlation is performed with respect to the signals from both AE detection means 5X, 5Y to calculate correlation characteristics. Here, a noise signal becomes non-impulse data to be canceled. The crack position measuring means 7 operates the shift from the center of correlation characteristics to detect the position of the crack developed in the material to be tested. |
