[Radioactive and radiation standards (II).  2. Standard gamma ray sources for exposure/rate measuring instrument calibration (1) (author's transl)].
D004781:Environmental Exposure; D005720:Gamma Rays / Q000592:standards*; D011829:Radiation Dosage; D011839:Radiation, Ionizing / Q000592:standards*; D011874:Radiometry / Q000295:instrumentation*; D012015:Reference Standards