Phased array ultrasonic testing is based on principles of wave physics. The term phased refers to the timing, and the term array refers to the multiple elements. The PA probe consists of many small elements, each of which can be pulsed separately. One element is pulsed first, and emits a pressure wave that spreads out like a ripple on a pond (largest semicircle). The next element is pulsed, and emits a ripple that is slightly smaller than the first because it was started later. The process continues down the line until all the elements have been pulsed. The multiple waves add up to one single wave front travelling at a set angle. Beam steering and focusing capabilities are key in enhancing resolution, which results in faster inspection time and increased probability of detection.
Unlike conventional and automated ultrasonic testing, which is performed for fixed angles of 45, 60 and 70 degrees, phased array testing can cover all angles in this range simultaneously. This is significant as a single phased array inspection can cover all angles from 40 to 75 degrees and displays the image in real time. The real time image is a direct superimposition of the ultrasonic illumination on the test piece and is easy to interpret. Using swept angle S-scans, PAUT requires smaller surface distance for inspection compared to AUT or manual UT. PAUT can cover a large cross-section of the test piece from a single probe location. Through the testing of sample plate and pipe sections, PAUT has proven its ability to detect weld flaws such as: toe cracks, center line cracks, lack of fusion, lack of penetration, slag and porosity. Additionally, the ability of PAUT to minimize the focal spot size at a defect location has allowed for increased accuracy of flaw sizing.
• More Information about a defects characteristics
• Ease of set-up
• Easy to Interpret
• Compatible software that can export measurements into
• A three-dimensional image that provides the exact location
• Ultrasonic waves successfully interact with planar defects.
• The scan is in real time, so the operator can see potential
problems as soon as the transducer(s) crosses over it.
• A flaw can be immediately examined without additional
setup or development.
• There is no radiation / inherent hazard.
• It is not necessary to clear an area for testing, nor is it
necessary to stop production.
• Only one inspector is required.