ARRAY SENSOR FOR TRANSMITTING AND RECEIVING ULTRASONIC WAVES, ULTRASONIC DETECTOR AND DETECTION METHOD BY ULTRASONIC WAVES FOR STABILIZING AND INCREASING DETECTION SENSITIVITY BY DETECTING DIFFRACTED WAVE IN OBJECT

摘要

PURPOSE: An array sensor for transmitting and receiving ultrasonic waves, an ultrasonic detector and an ultrasonic detecting method are provided to detect defect throughout the object securely by increasing the detection sensitivity stably. CONSTITUTION: A transmitting and receiving array sensor(14) has transmitting oscillator rows(15) and receiving oscillator rows(16). A focus(17) of a focusing sound field is electronically scanned in case of 1/2 of the total in adding the transmission angle of ultrasonic wave(16) to the receiving angle of diffracted wave(18) to be more than 30 angular degrees by the transmitting oscillators and the receiving oscillators. The end of defect(22) is detected from the received diffracted wave, and the depth of the defect is sized. The width of the oscillator in the oscillator row is 0.1 to 2 mm, and the gap between the oscillators is 0.05 to 0.2 mm.