| 摘要 |
A defect detecting method for detecting whether or not an object to be measured has a defect comprises the steps of vibrating the object to be measured, picking up the vibration, and detecting that a spectrum of the characteristic vibration of the object to be measured has a portion which is separated into two peaks. Also, a defect detecting apparatus comprises vibration means 25 for vibrating an object to be measured, pick up means 27 for picking up an vibration of the object to be measured and for converting the vibration into an electric signal, and computation process and determination means 30 for receiving the electric signal from the pick up means, for analyzing a spectrum of a characteristic vibration of the object to be measured, and for determining whether the defect is present or absent depending on whether a spectrum of a defect of the object to be measured is present or absent. The type of defect is indicated by the position of extra peaks in the spectrum in the first or second order main energy peaks. <IMAGE> |
