Radiography


Radiographic examination with x-ray films. These are placed behind the test object. A source of radiation (x-ray tubes, liner accelerator or radionuclide) is positioned in front of the test object. Due to the different absorption of radiation, local differences in the construction of the test object (different x-ray absorption coefficient) can be detected. This makes it possible to find localized defects, such as pores, cavities or inclusions. The film systems are produced in different classes, which differ in granularity (interior blurring) and sensitivity (exposure time), among other things. Detailed film types generally require longer exposure times and vice versa. In principle, a negative image is created on the film. This means that the areas of the image with a high amount of weakening (large amount of highly absorbent material) appear light and areas of the image with a low amount of weakening (low amount of poorly absorbent material) appear dark (Figs. 1 - 3, YXLON International GmbH, shows examples).

 

 

  • Fig. 1: Two-pole 450kV metal-ceramic x-ray tubeshave been specially developed in order to test sections ofhighly absorbent materials with thick wallssuch as iron and steel castings. This image shows the  completesystem in addition to the x-ray tubes (YXLON International GmbH, Hamburg)
  • Figure 2:  Defects in a weld detected using radiographic examination (YXLON International GmbH, Hamburg)
  • Fig. 3: Example of how radiography is used (YXLON International GmbH, Hamburg)