David W Telford, Thomas S Peat: Ultrasonic inspection of tube to tube plate welds. United Kingdom Atomic Energy Authority, William R Hinds, June 10, 1986: US04593568 (26 worldwide citation)

To monitor the deterioration of a weld (10) between a tube (11) and tube plate (12) which has been repaired by a repair sleeve (14) inside the tube and brazed at one end to the tube, ultrasound from a crystal (21) at the end of a rod (24) is launched into the tube through the braze (15) and allowed ...