METHOD AND APPARATUS FOR NONDESTRUCTIVE INSPECTION

摘要

PROBLEM TO BE SOLVED: To obtain a nondestructive inspection apparatus which is of a simple constitution and with which a measurement can be performed with satisfactory accuracy. SOLUTION: A sine-wave oscillator 1 generating a sine-wave signal whose frequency is changed continuously in a prescribed frequency range is installed. The sine-wave signal from the sine-wave oscillator 1 is converted into a mechanical vibration so as to be applied to a tile 11 to be inspected. The mechanical vibration generated at the tile 11 to be inspected is detected in a point separated from its application point. The detected mechanical vibration is converted into an electrical signal. The converted electrical signal is multiplied by the sine- wave signal from the sine-wave oscillator 1. The level of the electrical signal obtained by their multiplication is compared with a prescribed threshold value. Whether the tile 11 to be inspected is exfoliated or not is judged.