PENCIL-SHAPED LOCAL WATER PENETRATING ULTRASONIC PROBE AND METHOD OF DETECTING FLAW OF WELDED PART USING THE SAME

PROBLEM TO BE SOLVED: To provide an ultrasonic probe capable of accurately detecting flaws even in a fillet welded part, where the detection capacity of flaws is pool and the evaluation of the height of the flaw is difficult. SOLUTION: The pencil-shaped local water penetrating ultrasonic probe 1 has a conical (with its tip cut in conical shape) pencil shaped leading end having the hollow structure part 1e surrounded by a casing 1a. A focus type vibrator 1b is provided in the hollow structure part 1e on the rear end side thereof. A hollowed structure part 1e is filled with water in a measuring state and the shape of the vibration surface of the focusing type vibrator 1b is formed, so that the ultrasonic waves generated by the vibration of the vibrator to propagate through water are converged to the leading end part of the pencil- shaped local water-penetrating ultrasonic probe 1.