The JRC applied six measurement techniques to standardise the activity of an ²⁴¹Am solution in the frame of the 2003 key comparison CCRI(II)-K2.Am-241. The methods used were alpha-particle counting at a defined small solid angle, high-efficiency particle and photon counting with a windowless 4π CsI(Tl) sandwich spectrometer, 4π alpha counting with a pressurised proportional counter, alpha-gamma coincidence counting and sum counting with a small pressurised proportional counter and a NaI(Tl) well detector, and 4π counting with a liquid scintillation counter. All results were consistent and an unusually low measurement uncertainty of 0.054% was achieved. An overview is presented of the outcome of the key comparison exercise, which demonstrates international equivalence.

JRC在 2003 年关键比较 CCRI(II)-K2.Am-241 的框架内应用了六种测量技术来标准化²⁴¹ Am 溶液的活性。使用的方法是在定义的小立体角下进行 α 粒子计数、使用无窗 4π CsI(Tl) 夹层光谱仪进行高效粒子和光子计数、使用加压正比计数器进行 4π α 计数、α-γ 符合计数和总和计数使用小型加压正比计数器和 NaI(Tl) 井检测器，以及使用液体闪烁计数器进行 4π 计数。所有结果都是一致的，并且实现了 0.054% 的异常低测量不确定度。概述了关键比较工作的结果，证明了国际等效性。