The defective form discrimination modulo null which uses the electronic scanning-type ultrasonic crack inspect

摘要

PURPOSE:To understand a reflection directional pattern extending over an extensive azimuth by receiving an ultrasonic beam transmitted by only a prescribed number of vibrators in about the center part by switching it successively in the arrangement direction at every vibrator or at every plural pieces of vibrators. CONSTITUTION:An ultrasonic beam 4T deflected or focused suitably is transmitted by only a vibration group 13 consisting of a prescribed number of vibrators 2 in about the center part of an array probe 1. Subsequently, by following up the transmission of the beam 4T, a reflected wave 4R for forming a sound field distribution having a directional pattern by a dimension and a shape of a defect 6 is reflected from the defect 6 of a body to be inspected 5. Next, the beam is received and recorded by executing a linear scanning along its arrangement direction at every vibrator 2 or at every plural pieces of vibrators (1)-(3) and switching successively an intensity distribution of the reflected wave 4R. In such a case, a transmission/reception timing control of each vibrator 2 is executed by a transmitting/receiving vibrator switching part 7. In such a way, a reflection directional pattern can be measured by a distance resolution of every plural vibrators extending over a wide range, and an extremely detailed shape characteristic can be detected efficiently.