1.1 本指南涵盖了用于对聚合物样品进行SEM/EDS分析的法医实验室人员的推荐技术和程序。 1.2 本指南描述了聚合物SEM/EDS分析中使用的各种技术和程序，包括样品处理和制备、仪器操作条件以及光谱数据收集、评估和解释。 1.3 在扫描电子显微镜和X射线显微分析等文本中可以找到许多主题的理论方面 ( 1. ) . 2. 1.4 本指南旨在适用于更广泛的分析方案（例如，指南 E1610 , E3260 )用于聚合物样品的法医分析。 SEM/EDS分析可以提供有关聚合物材料来源之间潜在关系的额外信息。 1.5 本指南旨在供受过必要的正规教育和专业培训的合格法医学从业人员使用（见实践） E2917 , E3233 和 E3234 )，并表现出熟练的司法案件处理能力。 1.6 以国际单位制表示的数值应视为标准值。由于通用性，本标准中还包括其他测量单位（如keV）。 1.7 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。 1.8 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====== 4.1 本指南旨在建议和协助分析员制备SEM/EDS用聚合物样品（例如油漆和胶带），通过SEM/EDS收集数据，以及解释这些分析产生的图像和数据。 4.2 当聚合物被构造成层状材料时，对每个聚合物层分别进行SEM/EDS分析。 这种分析可能会受到不可识别的层结构的阻碍（例如，涂抹、层系统内的不规则偏析）。 4.3 SEM-EDS数据可用于: 4.3.1 层说明- SEM图像可以深入了解样品的层结构。 4.3.2 纹理说明- SEM图像和元素图提供了对纹理的深入了解（例如，表面形貌、夹杂物分布）。 4.3.3 元件标识- 测定样品层中检测到的元素。 4.3.4 相对元素丰度测定- EDS光谱允许比较样品中元素的相对丰度。 4.4 在法医聚合物比较的背景下，SEM/EDS结果的评估旨在深入了解以下法医任务: 4.4.1 结构、纹理和元素数据的比较。 4.4.2 支持其他仪器的结果（例如，从离散颗粒获得的EDS光谱中存在钙、氧和碳，表明在红外光谱中观察到碳酸钙的存在）。参考指南 E2937年 和 E3085 了解更多详细信息。 4.4.3 考虑到某些元素、层结构或纹理的存在，结果的重要性。

1.1 This guide covers recommended techniques and procedures intended for use by forensic laboratory personnel that perform SEM/EDS analyses on polymer samples. 1.2 This guide describes various techniques and procedures used in the SEM/EDS analysis of polymers that include sample handling and preparation, instrument operating conditions, and spectral data collection, evaluation and interpretation. 1.3 The theoretical aspects of many of the topics presented can be found in texts such as Scanning Electron Microscopy and X-ray Microanalysis ( 1 ) . 2 1.4 This guide is intended to be applied within the scope of a broader analytical scheme (for example, Guides E1610 , E3260 ) for the forensic analysis of a polymer sample. An SEM/EDS analysis can provide additional information regarding the potential relationships between the sources of polymeric materials. 1.5 This guide is intended for use by competent forensic science practitioners with the requisite formal education, discipline-specific training (see Practices E2917 , E3233 , and E3234 ), and demonstrated proficiency to perform forensic casework. 1.6 The values stated in SI units are to be regarded as standard. Other units of measurement are included in this standard where applicable as a result of common usage (for example, keV). 1.7 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. 1.8 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 ====== 4.1 This guide is intended to advise and assist the analyst in the preparation of polymer samples (for example, paint and tape) for SEM/EDS, the collection of data by SEM/EDS, and the interpretation of images and data resulting from these analyses. 4.2 When polymers are constructed as layered materials, SEM/EDS analysis is conducted on each polymeric layer individually. This analysis can be hindered by a non-discernable layer structure (for example, smear, irregular segregation within the layer system). 4.3 SEM-EDS data can be useful in: 4.3.1 Layer Elucidation— SEM images provide insight into the layer structure of a sample. 4.3.2 Texture Elucidation— SEM images and elemental maps provide insight into the texture (for example, surface topography, distribution of inclusions). 4.3.3 Element Identification— Determination of the elements detected in a sample layer. 4.3.4 Relative Elemental Abundance Determination— An EDS spectrum permits the relative abundance of elements in samples to be compared. 4.4 In the context of a forensic polymer comparison, the evaluation of SEM/EDS results are intended to provide insight into the following forensic tasks: 4.4.1 Comparison of structure, texture, and elemental data. 4.4.2 Support for results from other instruments (for example, the presence of calcium, oxygen, and carbon in the EDS spectrum obtained from discrete particles indicates the presence of calcium carbonate as observed in an infrared spectrum). Refer to Guides E2937 and E3085 for further details. 4.4.3 Significance of results given the presence of certain elements, layer structures, or textures.