NONCONTACT ACOUSTIC INSPECTION DEVICE AND NONCONTACT ACOUSTIC INSPECTION METHOD

摘要

PROBLEM TO BE SOLVED: To improve performance for detecting a defective part in a noncontact acoustic inspection method by removing an adverse effect due to an excited acoustic wave made incident on an optical detection system in an inspection device of vibrations inside a solid to be utilized for internal defect detection or the like of a concrete structure.SOLUTION: By using acoustic waves limited to the specific time, and paying attention to the time structure of direct acoustic waves or reflected acoustic waves from a periphery structure, influence on an optical detection system by such acoustic waves is removed, and by using only object signals to be optically detected, an adverse effect due to an excited acoustic wave is reduced and highly accurate detection of a target defect is made possible.