Remarks when applying radiographic testing

Radiographic testing as nondestructive is extensively used for internal defects detection in weldments. It is excellent to detect defects having volume such as blow hole etc. and the discrimination in defect kind of shape is easy. Points in the radiographic testing with X-ray film are explained. (1) In radiography of weldments, too high or too low density in the radiograph is not satisfactory for defects detection. (2) Even in a radiograph meeting the discrimination requirement in the transmissivity meter, the detection of planar defects (like inferior fusion etc.) differs with combination of the radiation source and photosensitive material. (3) Detection of planar defects tends to be influenced by the direction of irradiation. (4) Excess metal in the weldment adversely influences the defects detection. (Mori, K.)