| 摘要 |
PURPOSE:To detect the presence of the different hardness part in an object to be measured by detecting that a spectrum is separated into two spectra from the vibration applied to the matter to be measured and picked up therefrom. CONSTITUTION:The object to be measured placed on a measuring stage 24 is vibrated by a vibrator 25 and the vibration thereof is detected in a non- contact state by the sensor 27 of an output vibration receiving apparatus 26 to be converted to an electric signal. The inherent signal of the object to be measured is subjected to spectrum analysis on the basis of the electric signal by an operational processing/judging apparatus 30 and it is judged whether the peak of the spectrum of vibration due to the different hardness part in the object to be measured is present in the vicinity of the peak of the fundamental inherent vibration spectrum of the object to be measured. When there is a different hardness part in the object to be measured in this spectrum analysis, the spectrum processed by the inherent vibration of the object to be measured in separated into two spectra and, therefore, by detecting said spectra, the presence of the different hardness part can be detected. |
