radiographic examinations

X-ray and gamma tests have the properties of penetration through materials such as metals, concrete, plastics. The passage of rays through an object of various types of material and thickness causes different intensity of the beam behind the object. Also, the void inside the material that is not visible from the outside reduces the thickness of the material and thus causes less radiation attenuation than in a cross-section free from defects. The "amount of radiation" behind the void is greater, so in the radiograph, the void will be represented by a shading larger than the surroundings. In this way, X-rays and gamma rays can detect internal defects in materials and their welded joints. A radiographic film is used to visualize the overexposed object. The exposed film is subjected to photo-chemical treatment in the dark to obtain an image. It is also the most laborious and demanding examination.