Abstract: A method includes: an arrangement step of arranging a phased array probe including a plurality of oscillators each of which is capable of emitting ultrasonic waves on an end surface of the rotor disc, in a parallel state in which the plurality of oscillators are arranged along a circumferential direction of the rotor disc; a first transmission step of emitting ultrasonic waves from the plurality of oscillators in the parallel state, while a timing of emitting the ultrasonic waves from each of the oscillators is controlled in a first emission pattern, and receiving reflection waves of the ultrasonic waves; and a second transmission step of emitting ultrasonic waves from the plurality of oscillators in the parallel state, while the timing of emitting the ultrasonic waves from each of the oscillators is controlled in a second emission pattern different from the first emission pattern, and receiving reflection waves of the ultrasonic waves.

Abstract: An ultrasound flaw detection device which detects abnormalities within a tube while moving in the tube by pressure of water flow. The ultrasound flaw detector includes an ultrasound probe (11) which emits an ultrasound wave from an inside of the tube to a tube wall and receives an echo signal, a pulser-receiver (12) which transmits a pulse signal to the ultrasound probe and to which the received echo signal is inputted, a memory unit (14) which stores the received echo signal, a control unit (15) which controls transmitting timing of the pulse signal from the pulser-receiver to the ultrasound probe and controls writing of the received echo signal to the memory unit, and a power supply unit (19); a flexible member (25) which connects the plurality of parts of the ultrasound flaw detector; and a centering member (26) which keeps the ultrasound probe approximately centered within the tube.

Abstract: A method includes: an arrangement step of arranging a phased array probe including a plurality of oscillators each of which is capable of emitting ultrasonic waves on an end surface of the rotor disc, in a parallel state in which the plurality of oscillators are arranged along a circumferential direction of the rotor disc; a first transmission step of emitting ultrasonic waves from the plurality of oscillators in the parallel state, while a timing of emitting the ultrasonic waves from each of the oscillators is controlled in a first emission pattern, and receiving reflection waves of the ultrasonic waves; and a second transmission step of emitting ultrasonic waves from the plurality of oscillators in the parallel state, while the timing of emitting the ultrasonic waves from each of the oscillators is controlled in a second emission pattern different from the first emission pattern, and receiving reflection waves of the ultrasonic waves.

Abstract: It is intended to provide an ultrasound flaw detection device of an immersion-type that is inserted into a tube and is capable of moving smoothly within the tube just with water pressure, as well as an ultrasound flaw detection system.