| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic corrosion diagnostic method and its device capable of determining the progressing of corrosion of the back face accurately, by directly contacting a sensor with structural material on which a paint film is formed for rust- prevention or protection, without smoothing the surface of the structural material. SOLUTION: A sensor 3 is brought into contact with the surface of an optical position of an object to diagnose through an attenuation member (b), and an echo ratio (PF1/PF0) of ultrasonic wave on the interface between a paint film 1b on the surface and a sound layer 1a of the object to be diagnosed is obtained, and an echo ratio (PF1/PFX) on the back face of the object to be diagnosed is obtained from the echo ratio (PF1/PF0). And besides, a sensor 4 contacts the surface without interposing the retarding member (b), and the thickness of the object to be diagnosed and the amplitude of a reflected wave are obtained from the reflected wave of the ultrasonic wave on the back face, and the amplitude of the reflected wave is corrected with a reciprocal (PFX/PF1) of the echo ratio (PF1/PFX) on the back face, and the corrosion state on the back face of the object to be diagnosed is diagnosed from a master curve by the thickness of the object to be diagnosed and the corrected amplitude of the reflected wave. |
