基本信息
摘要：942,609. Radiographic techniques. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. July 19, 1962 [Aug. 25, 1961], No. 30703/61. Heading H5R. A method for the radiographic examination of materials having low absorption coefficients comprises contacting the parts to be examined with a volatile radiopaque fluid whose linear absorption coefficient is greater than twice that of the material of the specimen, effecting radiography, and removing the fluid by heating. The method may be applied to beryllium, beryllia or graphite which are commonly used in nuclear reactors, and the liquid, which may be applied by dipping, vacuum impregnation or vapour phase contacting, is a halogensubstituted aromatic or aliphatic hydrocarbon, e.g. carbon tetrachloride, bromobenzene, tetrabromethane or perchlorethylene. Removal of the halogen compounds below a level of 10-20 p.p.n. is effected by a simple treatment in a vacuum furnace at 95‹ C. for 30 hours, or at 400‹ C. for 2 hours. To detect microcracks, a thin film of the liquid is trapped over the surface of the specimen by using a transparent impermeable envelope, e.g. Cellophane (Registered Trade Mark).
摘要附图：
