Both conventional and phased array ultrasonic instruments utilize high-frequency sound waves to check the internal structure of a test piece or measure its thickness. They both rely on the same basic laws of physics that govern sound wave propagation. Similar concepts are employed in both ultrasonic technologies to present ultrasonic data.
Phased array instruments, on the other hand, are naturally multichanneled as they need to provide excitation patters(focal laws) to probes with 16 to as many as 256 elements. Unlike conventional flaw detectors, phased array systems can sweep a sound beam from one probe through a range of refracted angles, along a linear path, or dynamically focus at a number of different depth, thus increasing both flexibility and capability in inspection setups.
Phased array imaging provides the user with the ability to see relative point-to-point changes and multiangular defect responses, which can assist in flaw discrimination and sizing. While this can seem inherently complex,it can actually simplify expanding inspection coverage with increased detection by eliminating the complex fixtures and multiple transducer that are often required with conventional UT inspection methods.