Immersion transmit-receive longitudinal phased array probe for stainless steel

The difficulties associated with the ultrasonic inspection of stainless steel welds are well known and researchers around the world are working on the problem of improving the inspection quality. There are many issues associated with inspection, including accessibility and critical defect sizes, but the most important issue regards the accurate positioning, sizing and characterisation of flaws. Recently, the use of phased array technology to address these issues has been implemented and studied by various institutions and organisations. An immersion-coupled twin-crystal 2D matrix phased array transducer was developed in order to improve the signal-to-noise performance and enhance the positioning and sizing accuracy. The Transmit-Receive Longitudinal (TRL) probe was optimised for inspection from near surface (sub-clad) to around 50 mm in thickness.