To maintain the reliability and soundness in weld joints, Ultrasonic angle beam testing has been conducted in the past. Recently the weld quality has been improved, so the high heat input welding method has been widely adopted, the strength of construction has been declined for increasing weld defects. For this reason the conventional ultrasonic angle beam testing has been weak to detect large and hazardous defects in defect height. This paper describes the easy and reasonable detection and evaluation by comparison if probe's frequencies, angle of refraction, and element sizes.
