| 摘要 |
PROBLEM TO BE SOLVED: To provide air-coupled ultrasonic test equipment that ensures high ultrasonic testing accuracy even if an inspection object is a multi-layer structure where no transverse wave is generated due to mode change.SOLUTION: A multi-layer structure is employed as an inspection object (3). An air- coupled ultrasonic test equipment includes: a longitudinal ultrasonic wave transmitter (5) that transmits toward a measurement point on the inspection object (3) in the air atmosphere a longitudinal ultrasonic wave in an open-tube resonance frequency band including a center frequency f which satisfies a condition of f≒V*N/(2 t) (N is a positive integer), provided that the thickness of the inspection object is t, and the sonic speed of a longitudinal ultrasonic wave propagating in the inspection object is V; and a longitudinal ultrasonic wave receiver (6) that receives the longitudinal ultrasonic wave transmitting through the inspection object (3). |
