Non Destructive Testing(NDT) subject

Table 5.1 below shows the approximate half value layer (HVL) for various materials when radiation is from a gamma-ray source. Based on the HVL value, which material is better as a shielding material for gamma-ray between lead and steel? Why? (5 marks) Table 5.1 Half-Value Layer for selected shielding materials In Radiographic Testing (RT), interpretation of the radiographs must be undertaken by trained and experienced radiographers. Radiography of flat plates and cylinders large enough to permit entry for placement of the film is a relatively simple operation. Radiography of pipes, however, where access to the bore to place the film is not possible presents some problems and terms such as single wall single image (SWSI) and double wall single image (DWSI) are used as shorthand to identify the various techniques that may be used. With aid of diagram/s, describe when and how both SWSI and DWSI are applied during RT. For single wall technique, suggest when panoramic view is more relevant to be used compared to single image