1.1 本规程包括通过简单制备和使用高分辨率伽马射线探测器计数，对环境介质（例如水、土壤、植被、食物）中的放射性核素进行量化。由于该实践是为快速分析而设计的，因此没有采取广泛的努力来确保均匀性或理想的样本计数条件。 1.2 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本规程用于快速测定环境介质中的γ放射性核素。测试结果可用于确定样品中这些放射性核素的放射性是否超过相关事件或应急响应的行动水平。检测限取决于样本量、计数配置和使用的检测器系统。 5.2 在大多数情况下，相对于探测器而言，直径大、高度短的样品容器将提供最佳伽马射线- 射线检测效率。对于水或其他低Z材料（例如，植被）的样品，重入式或马里内利式烧杯可能产生最佳的γ射线检测效率。 5.3 与校准相比，样品材料的密度和样品容器的物理参数（例如，直径、高度、材料）可能对样品分析的准确性产生重大影响。因此，理想的校准材料和容器（通常称为“几何形状”）将与待分析的样品完全相同。样品容器或样品基质的差异可能会在探测器响应中引入显著误差，尤其是在低伽马射线能量下。如果无法获得精确的校准几何形状，则应尽一切努力解释这些差异。 5.4 本规程使用可通过国家计量研究所（NMI）（如美国国家标准与技术研究所（NIST）和英国国家物理实验室（NPL））追溯到SI的标准，在选定的特定几何形状中建立了经验伽马射线光谱仪校准，以确保容器、密度、，标准品的成分与样品的成分尽可能接近。然而，在某些情况下，使用数学建模或外推到替代几何形状来修改此类初始校准可能是有益的。根据分析过程的测量质量目标，如果包括对不确定性估计的适当补偿，则可以使用此类模型。 成功分析方法验证参考物质（MVRM）最能支持此类校准模型的使用。 5.5 本规程涉及环境介质中大量γ放射性核素的分析。本规程应适用于具有类似物理特性的非环境介质（例如，尿液、碎屑或碎石）。关键决定 相似的物理特性 是指能够证明伽马能谱系统对样品配置的响应与校准系统的响应适当相似。 5.6 对于低伽马射线发射能量（<100 keV）的放射性核素的分析，样品基质中伽马射线的自吸收可能对检测和量化产生重大不利影响。 用户应验证仪器校准是否适当考虑了样品基质可能产生的任何自吸收。 5.7 通常可用的能量和效率校准标准涵盖约60 keV至1836 keV的能量范围。使用效率校准能量范围以外的伽马射线峰值获得的结果将具有更大的不确定性，这在本规程的不确定性计算中没有考虑。应特别注意审查该范围外的效率校准值和效率曲线的形状。为了更准确地分析γ射线能量在该范围之外的放射性核素，建议使用一种校准标准，其中包括γ射线能量跨越相关放射性核素能量范围的放射性核素。

1.1 This practice covers the quantification of radionuclides in environmental media (for example, water, soil, vegetation, food) by means of simple preparation and counting with a high-resolution gamma ray detector. Because the practice is designed for rapid analysis, extensive efforts to ensure homogeneity or ideal sample counting conditions are not taken. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This practice was developed for the rapid determination of gamma-emitting radionuclides in environmental media. The results of the test may be used to determine if the activity of these radionuclides in the sample exceeds the action level for the relevant incident or emergency response. The detection limits will be dependent on sample size, counting configuration, and the detector system in use. 5.2 In most cases, a sample container which is large in diameter and short in height relative to the detector will provide the best gamma-ray detection efficiency. For samples of water or other low-Z materials (for example, vegetation), the re-entrant or Marinelli-style beaker may yield the best gamma-ray detection efficiency. 5.3 The density of the sample material and physical parameters of the sample container (for example, diameter, height, material) may have significant consequences for the accuracy of the sample analysis as compared to the calibration. For this reason, the ideal calibration material and container (often referred to as ‘geometry’) will be exactly the same as the samples to be analyzed. Differences in sample container or sample matrix may introduce significant errors in detector response, especially at low gamma-ray energies. Every effort should be made to account for these differences if the exact calibration geometry is not available. 5.4 This practice establishes an empirical gamma-ray spectrometer calibration using standards traceable to the SI via a national metrology institute (NMI) such as the National Institute of Standards and Technology (NIST) in the United States and the National Physical Laboratory (NPL) in the United Kingdom in a specific geometry selected to ensure that the container, density, and composition of the standard matches that of the samples as closely as possible. However, in some cases it may be beneficial to modify such initial calibrations using mathematical modeling or extrapolations to an alternate geometry. Use of such a model may be acceptable, depending on the measurement quality objectives of the analysis process, and provided that appropriate compensation to uncertainty estimates are included. The use of such calibration models is best supported by the successful analysis of a method validation reference material (MVRM). 5.5 This practice addresses the analysis of numerous gamma-emitting radionuclides in environmental media. This practice should be applicable to non-environmental media (for example, urine, debris, or rubble) that have similar physical properties. The key determination of similar physical properties is the ability to demonstrate that the gamma spectrometry system response to the sample configuration is suitably similar to that for which the system is calibrated. 5.6 For the analysis of radionuclides with low gamma-ray emission energies (<100 keV), self-absorption of the gamma-rays in the sample matrix can have a significant adverse effect on detection and quantification. The user should verify that instrument calibrations appropriately account for any self-absorption that may result from the sample matrix. 5.7 Commonly available energy and efficiency calibration standards cover the energy range of approximately 60 keV to 1836 keV. Results obtained using gamma-ray peaks outside the efficiency calibrated energy range will have greater uncertainty not accounted for in the uncertainty calculations of this practice. Great care should be taken to review the efficiency calibration values and the shape of the efficiency curve outside this range. For greater accuracy in the analysis of radionuclides whose gamma-ray energies are outside this range, a calibration standard which includes radionuclide(s) whose gamma-ray energies span the energy range of radionuclides of interest is advised.