title: Improved photographic leak test system for sealed sources of radium 226.
mesh_terms: D010781:Photography; D011834:Radiation Monitoring / Q000295:instrumentation*; D011883:Radium / Q000032:analysis*; D011886:Radon / Q000032:analysis; D013679:Technology, Radiologic / Q000295:instrumentation
chemical_list: D011886:Radon; D011883:Radium