The roots of modern nondestructive testing (NDT) date back around one hundred years. In the 1920s, there was already a growing awareness of the application of methods such as radiography within the medical field, following German physicist Wilhelm Conrad Röntgen’s Nobel Prize for discovering X-rays in 1895.
NDT dates back significantly further, though: it is reported that flour and oil were used in ancient Rome to find cracks in marble slabs, and that for centuries, blacksmiths used sonic NDT to listen to the ring of different metals as they were being hammered into shape. However, one of the first recorded uses of NDT was in England in 1868 when Saxby used the magnetic characteristics of a compass to detect cracks in gun barrels.