Exposure times of one-millionth of a second or less can be achieved through the use of specially designed high voltage generating equipment and X-ray tubes. Stereo Radiography Radiograph Viewing Setupįlash radiography is a special type of radiography that is used to produce a single stop motion image or a series of sequential images of high-speed phenomena. The eyes sec the X-ray representation of the part just as the X-ray tube exposed the actual part. With respect to the tube during the exposures. The two Eyes take the place of the two positions of the focal spot of the X-ray tube, and the radiograph as viewed in mirrors or prisms occupies the same position with respect to the eyes as did the films In fact, the conditions of viewing the radiographs should be analogous to the conditions under which they were exposed. It is important to remember that the radiograph exposed in the right shift position of the tube is viewed by the right eye and the one exposed by the left shift position is viewed by the left eye. As in normal vision, the brain integrates the two images into one in which the various features stand out in relief in true perspective and in correct spatial relation. After processing, the two radiographs are viewed in a stereoscope, a device that by an arrangement of prisms or mirrors permits each eye to see only one of the stereo radiographs. To duplicate this stereoscopic vision in radiography requires two radiographs made from two positions of the X-ray tube separated by the normal human interpupillary distance. Stereo radiography is a radiographic method using two separate radiographs made with a source shift exactly parallel to the film plane, as in Figure 10.5. This can be overcome using a radiography technique called stereo Radiography. One of the limitations of conventional film based radiography is that it doesn’t provide the depth of the discontinuity. Here in this we article we will learn about different techniques of radiography. Hence many times advanced radiography techniques are used. One often comes to words NDT Method and NDT Techniques and uses them interchangeably however it is not like that.Ī method is one of the disciplines of NDT.įor example, ultrasonic testing within which various test techniques may exist.Ī test technique is a category within an NDT method įor example, immersion ultrasonic testing.įilm-based conventional radiography is still prominent in the manufacturing industry, but there are times and applications when required results are cannot be obtained from conventional film-based radiography. INTRODUCTION TO RADIOGRAPHIC TESTING(RT). We have posted a detailed article about digital radiography in our Blog : Typical Setup of conventional film based radiography These transmitted rays are recorded on an imaging media which on further processing gives a radiographic image of the test object. In passing through the material some of these rays get absorbed and transmitting the rest of the rays. Penetration depends upon thickness, the density of material and size of source being used. X-rays and gamma rays can even penetrate materials that don’t transmit light. Radiography testing Uses the ability of x-rays and gamma rays to penetrate materials. THE BASIC PRINCIPLE OF RADIOGRAPHY TESTING : To learn more about the history of radiography testing read our blog HISTORY OF NON-DESTRUCTIVE TESTING. X-rays were initially developed for medical applications. Radiographic testing includes passing of X-rays or Gamma Rays through the test item from one side and recording the rays on an imaging media on the other side giving a permanent visual record of the internal structure of the test items. Radiography is a volumetric NDT test method used to determine internal flaws in castings and Welds.
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