METHOD FOR DETECTING ULTRASONIC PLATE WAVE AND METHOD FOR DETECTING DEFECT IN PIPING

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently receiving a plate wave obtained when an ultrasonic wave enters into piping and improving accuracy for detecting defects in the piping.;SOLUTION: The ultrasonic wave from an ultrasonic wave transmission oscillator 11 enters into the piping 20. An incident angle or a refraction angle of the ultrasonic wave entering into the piping 20 is uniformalized. The transmitted ultrasonic wave becomes the plate wave. A receiving oscillator 13 for detecting the ultrasonic plate wave detects components of the ultrasonic wave 23 emitted from the piping 20 to a medium 12 and having the refraction angle 90° - θ and a frequency range of 1-3 MHz (sinθ=C_W/C_L). All components of the ultrasonic wave corresponding to the defects in the piping can be substantially detected. The accuracy and efficiency for detecting the defects in the piping are improved. If the medium is polystyrene, θ is approximately 25°.;COPYRIGHT: (C)2004,JPO