TOFD originated from tip diffraction techniques which were first published by Silk and Liddington in 1975 which paved the way for TOFD. Later works on this technique are given in a number of sources which include Harumi et al.
The origins of TOFD can be traced back to tip diffraction methods initially published by Silk and Liddington in 1975. This paved the way for the development of TOFD. Further advancements in this technique are detailed in numerous publications, with notable contributions from Harumi et al.