Method and apparatus for phased array based ultrasonic evaluation of rail

In accordance with one embodiment, the present technique provides a testing apparatus for testing material integrity of an object. The exemplary testing apparatus includes a phased array transducer, which is disposed external to the object. The phased array transducer is configured to transmit a first set of ultrasonic signals and to receive a second set of ultrasonic signals. The testing apparatus further includes logic circuitry coupled to the phased array transducer. The logic circuitry is configured to dynamically control apertures for transmitting the first set of ultrasonic signals and receiving the second set of ultrasonic signals based on a region of interest and a testing speed.