ASNT

PART 2 History of Radiographic Testing

RÖNTGEN Wilhelm Conrad Röntgen (Figure 13) made his momentous discovery of X-rays on Friday, 8 November 1895, in his laboratory at the University of Würzburg in Germany. The importance of this new kind of ray was recognized immediately. The see-through property of X-rays created a sensation not only in the scientific community, but also in the popular press. By early January 1896, newspapers around the world carried news of these new rays and their ability to pass through f lesh and other materials. The newspaper accounts correctly predicted the tremendous impact that X-rays were to have on medical diagnosis. Researchers radiographed hundreds of different kinds of objects. Industrial applications were found almost immediately, in the sense that artillery shell casings were among the objects so examined. It was decades before routine nonmedical uses of X-rays became economically viable for many industries (Berger 1995). Clearly, the practical uses for X-rays have gone well beyond the early concepts. Immediate medical uses foreseen included setting of broken bones and location of foreign objects — bullets, pins, coins, and others. Medical applications have now expanded to include diagnosis of diseases such as tuberculosis, malfunctions such as blockages of the circulatory system, and the detection of many abnormalities, such as tumors and calcium loss in bones, as well as many medical therapies. X-rays are now used industrially to inspect manufactured products

Figure 13 Wilhelm Conrad Röntgen.

(metals and nonmetals), joints, assemblies, packages and baggage, and to identify and analyze materials. The methods include film radiography and f luoros- copy (the two methods Röntgen used), and the more modern techniques such as digital (electronic) radiography, computed radiography, tomography, backscatter imaging, radiation gauging, diffraction, f luorescence and others. Preliminary Work As a director of the Physical Institute at Würzburg, Röntgen had freedom to pursue scientific ideas that were of interest to him. In 1895, he began collect- ing the equipment needed to investigate lumines- cence effects. He studied early work by people

CHAPTER 1

16

Part 2