Using ultrasonic technology to test pipeline welds has increased significantly worldwide since ultrasonic equipment became available in the 1980s. This was due to considerable improvements made in the development of ultrasonic technology as well as a desire to explore the safety and environmental benefits created by reducing the use of radiation from traditional radiographic methods. As AUT Technology has evolved, it has created an industry desire for its more reliable, time-effective, cost-lessening and better weld defect detecting results. Currently Automated Ultrasonic Testing (AUT) is recognized as the most reliable and beneficial weld testing method. The preliminary AUT systems used probes to focus ultrasonic beams onto weld fusion line zones. These would then detect reflected energy from any areas lacking fusion.