Abstract: In an ultrasonic inspection system for inspecting the surface condition of an object or the existence or absence of internal defects in it by ultrasonically scanning the object with ultrasonic beams, which have been successively produced as a result of successive excitation of a number of array element oscillators (10.sub.1 -10.sub.n) arranged in a row, and then analyzing waves reflected by the object, reference data for individual ultrasonic beams (individual channels) are collected by ultrasonically scanning a reference material of defect-free uniform quality before ultrasonic inspection of the object. Correction values are prepared based on these reference data, and signals received by the ultrasonic scanning of the object are corrected by these correction values. According to one correction means, the ratios of the average value of reference values of the individual channels to the reference values of the individual channels are determined channel by channel.

Abstract: The present invention is directed to an ultrasonic flaw detector for inspecting the surface condition of a specimen or the existence or non-existence of one or more internal defects in the specimen by scanning the specimen with ultrasonic waves and analyzing waves reflected by the specimen. The ultrasonic flaw detector includes a number of array elements arranged in a line. The ultrasonic beam scanning of a specimen is performed by vibrating plural ones of the array elements to form a single ultrasonic beam and shifting vibration of the array elements one by one. Array elements are divided into plural blocks by a block selector. Ultrasonic scanning is simultaneously conducted in the respective blocks.

Abstract: A fan-shaped scanning flaw detecting apparatus which includes a probe provided with an ultrasonic wave transmitting-and-receiving array transducer arranged along a circular arc and an acoustic lens for converging and converting an ultrasonic beam transmitted/received by the array transducer into a substantially parallel beam. The apparatus also includes a scanning function section that sequentially switches the transmitting and receiving operation of a group of operative transducer elements of the array transducer so as to make the ultrasonic beam perform fan-shaped scanning. A picturizing processor section forms a sectional image of an object to be examined on the basis of an echo signal obtained from the object to be examined and a display section displays the sectional image. A position detecting section detects a position where the ultrasonic beam is incident to the object to be examined when the probe is moved along a surface of the object to be examined.