Abstract
Instead of radiographic test, ultrasonic test has been applied to nondestructive evaluation of butt welded joints. New type of tandem array transducer was developed. By the tandem array transducer, tandem probe test could be carried out without back and forth scanning. Higher detectability could be obtained by tandem probe technique than one probe technique for butt welded joint specimens. Fundamental investigation of development of new imaging system based on synthetic aperture focusing technique was conducted by the tandem array transducer. Separation of defect echo from bead echoes was also examined in the imaging system. Defect image could be obtained clearly by the new system.
