本标准规定了放射性核素γ射线发射率测量用铊活化碘化钠[NaI（Tl）]探测器系统的性能测试、校准和使用方法；放射性测定；以及伽马射线能量和强度的测定。它包括能量校准和效率校准。考虑以下三种技术: a） 总频谱计数（见4.1）采用了一种系统，对低能谱线以上的所有脉冲进行计数 阈值（见6.1、6.2和6。 3). b） 单通道分析仪（SCA）计数（见4.2）采用带计数a？窗户，a？建立了上下能量边界（见6.1、6.2和6.3）。 c） 多通道分析仪（MCA）计数（见4.3）采用多个计数窗口的系统。这种技术允许在不引入不可接受误差的情况下，减去全能量峰值下的连续统。 在光谱中出现重叠峰的情况下，MCA可以访问光谱- 剥离程序是必要的。本标准不包括此类情况。

This standard establishes methods for performance testing, calibration, and usage of thallium-activated sodium iodide [NaI(Tl)] detector systems for the measurement of gamma ray emission rates of radionuclides; the assay for radioactivity; and the determination of gamma ray energies and intensities. It covers both energy calibration and efficiency calibration. The following three techniques are considered: a) Total spectrum counting (see 4.1) employs a system that counts all pulses above a low-energy threshold (see 6.1, 6.2, and 6.3). b) Single-channel analyzer (SCA) counting (see 4.2) employs a system with a counting "window," which establishes upper and lower energy boundaries (see 6.1, 6.2, and 6.3). c) Multichannel analyzer (MCA) counting (see 4.3) employs a system in which multiple counting windows are utilized. This technique allows measurements for which the continuum under the full energy peak may be subtracted without introducing unacceptable error. In case of overlapping peaks in the spectrum, it is realized that an MCA with access to a spectrum-stripping program is necessary. Such cases are not covered by this standard.