FAAST-Fast Automated Angle Scan Technique

Since "Phased Array" systems appeared in the field of industrial testing, this technique only reproduced an ultrasonic beam equivalent to that of a single element transducer, offering however, in addition, the possibility of an electronic control of the ultrasonic beam direction and shape. These systems thus offer an increased flexibility of use, higher linear or angular scanning speed, together with a considerable advantage in terms of the volume of the probe-holder mechanics. However, this technique did not bring any improvement in terms of defect detection and characterization, as the reflected energy is still depending, like with single element probes, on the position of the transducer to the part and on the actual orientation of the defects. This paper describes a new method for processing the acoustic field received by a multi-element probe, which, at last, brings a solution to this endemic problem and the associated electronic device suitable for industrial applications. This method and system enable the detection and characterization, from a single ultrasonic pulse, of all types of defects, plane or spherical, situated in the acoustic field of the probe, whatever their orientation and allows, in addition, tolerance of guiding precision. As an example, the first industrial application being built by SOCOMATE using this method is an ultrasonic rail testing car providing in-track inspection at a speed of 100km/h.