Phased Array Ultrasonic Testing ( PAUT)

Ultrasonic phased array testing is a powerful NDT technology and one whose use is growing rapidly, however it can seem complex to a person who has not worked with it. This self-guided tutorial is a basic introduction to ultrasonic phased array testing, both for newcomers and for more experienced users who want a review of basic principles. It begins with what phased array testing is and how it works, then outlines some considerations for selecting probes and instruments, and ends with links to phased array application notes and a phased array glossary. In addition to text and illustrations it includes a series of interactive Flash files as learning tools. The benefits of phased array technology over conventional UT come from its ability to use multiple elements to steer, focus and scan beams with a single transducer assembly. Beam steering, commonly referred to sectorial scanning, can be used for mapping components at appropriate angles. This can greatly simplify the inspection of components with complex geometry. The small footprint of the transducer and the ability to sweep the beam without moving the probe also aids inspection of such components in situations where there is limited access for mechanical scanning. Sectorial scanning is also typically used for weld inspection. The ability to test welds with multiple angles from a single probe greatly increases the probability of detection of anomalies. Electronic focusing permits optimizing the beam shape and size at the expected defect location, as well as further optimizing probability of detection. The ability to focus at multiple depths also improves the ability for sizing critical defects for volumetric inspections. Focusing can significantly improve signal-to-noise ratio in challenging applications, and electronic scanning across many groups of elements allows for C-Scan images to be produced very rapidly.