1.1 本指南制定了一个协议，用于生成和报告可追溯到国际单位制或为水和环境行业服务的实验室中的认证标准物质的化学分析。 1.2 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。 1.3 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 本指南规定了水和环境实验室应满足的基本要求，这些实验室应生成并报告实验室客户希望可追溯到国际单位制的测试化学分析( 注1 )或可追溯到国际单位制的认证标准物质。化学分析的可追溯性很重要，因为它为比较不同测量系统的结果提供了统一的基础，并且因为它将这些结果与我们当前对物理定律的知识相关联( 注释2 ). 注1: 可追溯到国际单位制的认证标准物质是一种认证标准物质，其值可以通过与以国际单位制表示的参考（通常为国家或国际标准）的连续比较变化与规定的不确定度相关，例如以国际单位制进行的一次测量或以国际单位制认证的国家标准。 注2: 并非所有的化学分析结果都可以追溯到国际单位制，或可追溯到国际单位制的认证标准物质，例如浊度和/或总悬浮固体。 4.2 许多与水相关的实验室遵守ISO指南17025，并参与能力验证计划。与同一认证机构和能力验证提供者有联系的实验室可以在同一样本上报告统计上相似的结果。然而，一些测试方法和一些经认证的标准物质不支持可追溯到国际单位制的数据。因此，如果在同一样品上使用相同的不可追踪测试方法，与同一供应商无关的完全合规实验室可能会报告统计上不同的化学分析结果。如果他们使用可追溯到国际单位制的测试方法、测量设备和经认证的参考材料（如可用），则可以将这个问题降到最低。 4.3 虽然一些标准测试方法和认证的参考材料提供了可追溯到国际单位制的证据，但许多其他方法则没有。因此，在通过适当的文件确认更多试验方法和认证标准物质的可追溯性之前，并非所有实验室都能普遍满足所有可追溯分析的要求。 4.4 本指南的主要意义在于，它建立了一个共识，即为了使实验室产生可追溯的测量，它必须( 1. )清楚了解可追溯测量的用户需求( 2. )符合ISO指南17025中包含的国际公认质量体系要求( 3. )使用已证明可追溯到国际单位制的测试方法、测量设备和经认证的标准物质，以及( 4. )能够证明测量系统在进行测量时处于统计控制状态。 4.5 预计D19委员会将使用本指南为其标准的技术内容制定政策，这些标准可用于生成可追溯的化学分析。

1.1 This guide sets a protocol for generating and reporting chemical analyses that are traceable to SI units or to certified reference materials in laboratories that serve the water and environmental industry. 1.2 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. 1.3 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 establishes basic requirements which should be met by water and environmental laboratories that generate and report test chemical analyses which the laboratory client desires to be traceable to SI units ( Note 1 ) or certified reference materials traceable to SI units. Traceability of chemical analyses is important because it provides a uniform basis for the comparison of results from different measurement systems and because it relates those results to our current knowledge of physical laws ( Note 2 ). Note 1: A certified reference material traceable to SI units is a certified reference material whose value can be related with a stated uncertainty through an unbroken change of comparisons to stated references (usually national or international standards) in SI units, such as a primary measurement made in SI units or a national standard certified in SI units. Note 2: Not all chemical analysis results can be traceable to SI units or to certified reference material’s traceable to SI units, such as turbidity and or total suspended solids. 4.2 Many waters-related laboratories comply with ISO Guide 17025 and participate in Proficiency Testing Programs. Laboratories that are connected to the same accreditation bodies and Proficiency Test providers can be expected to report statistically similar results on the same sample. However, some test methods and some certified reference materials are not supported with data traceable to SI units. Therefore, fully compliant laboratories that are not connected to the same providers may report statistically different chemical analysis results if they used the same nontraceable test method on the same sample. This problem could be minimized if they used test methods, measurement devices, and certified reference materials that are traceable to SI units, where available. 4.3 Although some standard test methods and certified reference materials provide evidence of traceability to SI units, many others do not. Therefore, not all laboratories can be expected to universally meet all requests for traceable analyses until the traceability of more test methods and certified reference materials is recognized through appropriate documentation. 4.4 The primary significance of this guide is that it establishes a consensus that, in order for a laboratory to generate traceable measurements, it must ( 1 ) have a clear understanding of the needs of the user of the traceable measurements, ( 2 ) comply with the internationally accepted quality-system requirements included in ISO Guide 17025, ( 3 ) use test methods, measurement devices, and certified reference materials which have been shown to be traceable to SI units, and ( 4 ) be able to demonstrate that the measurement system was in statistical control at the time the measurements were made. 4.5 It is expected that this guide will be used by Committee D19 in setting policies for the technical content of its standards that are designated to be usable to generate traceable chemical analyses.