1.1 本规程为D19水委员会适用试验方法的精度和偏差的估计和表示建立了统一标准。ASTM标准“第A21节精度和偏差（强制性）”的形式和风格要求对测试方法中的精度和偏差进行说明原则上，本规程涵盖了所有测试方法。然而，本标准中提供的可变性方程仅适用于产生连续函数值的试验方法。 1.2 除非另有规定 1.4 , 1.5 和 1.6 该实践要求任务组提出一种新的测试方法，以进行协作研究，从中得出精度声明（整体和单一- 操作员标准偏差估计）和偏差。该实践为任务组在规划和进行精度和偏差的确定方面提供了一般指导。 1.3 这种做法要求对测试方法进行实质性修改的任务组也进行有限规模的协作研究（称为 ― 可比性研究），以评估修订对精度和偏差声明的影响。该实践为任务组进行此类有限规模的协作研究提供了指导。实质性修改的示例可能包括但不限于强制或允许的仪器、试剂、反应时间等的更改。 1.3.1 方法范围内适用水基质的变化可能构成本条款下的实质性修改。只有在经批准的合作研究中评估过的矩阵才能列入方法范围。人们认识到，“矩阵”一词通常是模糊的。指定基质类型的术语可以涵盖显著不同的化学成分，除非基质合成为标准组成。替代废水（实践 D5905 )就是这样一个定义的矩阵。就本实践而言，本要求的重要性在于帮助D19标准的用户确定方法对其样品的适用性。 应尽可能详细地描述评估矩阵，以最大限度地减少误用。 1.3.2 被认为值得额外合作测试的方法浓度范围扩展（即使没有被视为实质性的方法修改）应要求进行全面的合作研究，如中所述 7.1 通过 7.5 ，但仅在代表扩展范围的浓度下。注意，这种协作研究可能只涉及单个可重复基质中的单个浓度研究。 1.3.3 试验方法的修订是否包括实质性修改，应由委员会协商一致决定。 1.4 如果由于试验方法的性质或样品的不稳定性，全面协作研究在技术上不可行，则应进行技术上可行的最完整协作研究，以提供估计整体和单个操作员标准偏差的最佳可能有限基础。在某些情况下，如指南中所述，进行中间协作研究 D7847 可以提供适当的方法。人们认识到，有时即使是有限的合作研究也不可行。任何不符合本实践中规定的所有要求的合作研究计划都需要结果顾问的审查和建议，以及执行小组委员会D19技术操作科的批准。 1.4.1 可接受的研究示例为小组委员会D19.24就微生物方法进行的局部区域中间研究，因为样品固有的易腐性。这种中间协作研究满足与完全协作研究相同的自由度和参与者要求。他们涉及六名或六名以上完全独立的本地分析师，他们可以在约定的时间开始分析均匀样本。指导 D7847 可以为任务组、结果顾问和D19委员会执行小组委员会的技术操作科提供指导，以适当设计可接受的中间协作研究，用于测量高度易腐参数的测试方法。 1.4.2 如果在任何情况下都不可能提供具有足够稳定分析物浓度的同质样品，则单操作员精度声明可能符合本规程的要求。只要可能，应根据多个独立操作员生成的数据编制该声明，每个操作员对独立样本（特定基质类型）进行重复分析，这些样本通常在规定的浓度范围内（见 7.2.5.2 ( 3. )). 1.5 在进行研究时，满足本实施规程版本要求的合作研究将继续被视为精度的充分基础- 以及每种测试方法中要求的偏差声明。如果该研究不满足当前协作研究的最低要求，则应在精度和偏差声明中包含一份列出该研究缺陷的声明和对本段的引用，作为免除当前要求的依据。 1.6 D19委员会可通过主要委员会投票批准发布“初步”标准方法，期限不超过5年。初步标准必须至少包含单操作员精度和偏差声明，以及基于单操作员数据的质量控制部分。初步标准的发布取决于完整标准的批准 D2777 标准的协作研究设计。本段授权的精度和偏差声明应包括D19委员会批准的日期。 1.7 根据ASTM表格和样式手册第A21.2.3节，委员会可推迟新方法的实验室间研究，并在精度和偏差部分包含一项临时声明，该声明仅涉及单操作员精度（“重复性”）。本声明自首次发布之日起五年内有效。在这种情况下，应根据 7.6 . 1.8 在节中 12 ，本实践展示了以下示例性精度和偏差声明格式: ( 1. )产生数值测量的试验方法( 2. )根据程序中规定的标准，产生成功或失败的非数值报告的试验方法，以及( 3. )规定使用另一种ASTM试验方法中的程序的试验方法，仅需进行微不足道的修改。 1.9 所有研究，即使是不符合前几节中某些要求的研究，在进行前都应获得结果顾问的批准（见第节） 8. )竣工后（见第 13 ). 1.10 本规程满足规程的QC要求 D5847 . 1.11 这种做法的目的是，任务组尽一切努力保留其合作研究中的所有数据。 除非有确凿证据表明价值被排除，否则不应排除价值。结果顾问应与任务组密切合作，以实现这一目标。 1.12 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 遵循这一实践应产生精度和偏差声明，任何实验室都可以通过适当使用所研究的测试方法来实现。 这些精度和偏差声明为测试方法质量控制部分使用的通用限值提供了基础。或者，检测和定量值提供了大多数实验室应能够实现可靠检测并满足预期最低精度（表示为相对标准差）的估计水平。 5.2 该方法规定了测试方法适用的矩阵。协作测试在测试设计的限制范围内证实了编写。广泛测试只能使用代表性矩阵，因此结果不能暗示普遍适用性。 5. 3. 协作研究的基本假设是，测试的基质、测试的浓度和参与实验室是对书面测试方法的范围和适用性的代表性和公平评估。

1.1 This practice establishes uniform standards for estimating and expressing the precision and bias of applicable test methods for Committee D19 on Water. Statements of precision and bias in test methods are required by the Form and Style for ASTM Standards, “Section A21. Precision and Bias (Mandatory).” In principle, all test methods are covered by this practice. However, the variability equations provided in this standard are applicable only to test methods that yield continuous function values. 1.2 Except as specified in 1.4 , 1.5 , and 1.6 , this practice requires the task group proposing a new test method to carry out a collaborative study from which statements for precision (overall and single-operator standard-deviation estimates) and bias can be developed. This practice provides general guidance to task groups in planning and conducting such determinations of precision and bias. 1.3 This practice requires that a task group making a substantive revision to a test method also perform a limited-scale collaborative study (known as a ― comparability study) to evaluate the effect of the revision on the precision and bias statement. This practice provides guidance to task groups for conducting such limited-scale collaborative studies. Examples of substantive modifications may include, but are not limited to, changes in mandatory or allowable instrumentation, reagents, reaction times, etc. 1.3.1 Changes to applicable water matrices in the Scope of a method may constitute a substantive modification under this provision. Only matrices that have been evaluated in an approved collaborative study may be listed in the Scope of a method. It is recognized that the term “matrix” is generally vague. Terms specifying matrix types can cover significantly different chemical constituents, unless the matrix is synthesized to be of a standardized makeup. Substitute Wastewater (Practice D5905 ) is one such defined matrix. For purposes of this practice, the importance of this requirement is to assist the user of a D19 standard in determining the applicability of the method to their samples. Evaluated matrices should be described with as much detail as possible to minimize misapplication. 1.3.2 A method's concentration-range extension that is deemed to merit additional collaborative testing (even without a method modification that would otherwise be considered substantive) shall require a full collaborative study, as described in 7.1 through 7.5 , but only at concentrations representative of the extended range. Note that such a collaborative study could involve as little as a single concentration study in a single reproducible matrix. 1.3.3 Whether a revision to a test method includes substantive modification shall be determined by consensus of the Committee. 1.4 If a full-scale collaborative study is not technically feasible, because of the nature of the test method or instability of samples, the most complete collaborative study that is technically feasible shall be conducted to provide the best possible limited basis for estimating the overall and single-operator standard deviations. In some situations, an intermediate collaborative study as described in Guide D7847 may provide an appropriate approach. It is recognized that there may be circumstances when even a limited collaborative study is not feasible. Any collaborative study plan that does not meet all the requirements spelled out in this practice will require a review and recommendation by the Results Advisor and an approval by the D19 Technical Operations Section of the Executive Subcommittee. 1.4.1 Examples of acceptable studies are the local-area intermediate studies conducted by Subcommittee D19.24 on microbiological methods because of inherent sample perishability. Such intermediate collaborative studies meet the same degrees of freedom and participant requirements as full collaborative studies. They involve six or more completely independent local-area analysts who can begin analysis of uniform samples at an agreed upon time. Guide D7847 can provide guidance to the task group, the Results Advisor, and the Technical Operations Section of the Executive Subcommittee of Committee D19 on the appropriate design of an acceptable intermediate collaborative study for test methods that measure highly perishable parameters. 1.4.2 If providing homogenous samples with a sufficiently stable analyte concentration is not feasible under any circumstances, a statement of single-operator precision may meet the requirements of this practice. Whenever possible, this statement should be developed from data generated by multiple independent operators, each doing replicate analyses on independent samples (of a specific matrix type), which generally fall within specified concentration ranges (see 7.2.5.2 ( 3 )). 1.5 A collaborative study that satisfied the requirements of the version of this practice in force when the study was conducted will continue to be considered an adequate basis for the precision-and-bias statement required in each test method. If the study does not satisfy the current minimum requirements for a collaborative study, a statement listing the study's deficiencies and a reference to this paragraph shall be included in the precision-and-bias statement as the basis for an exemption from the current requirements. 1.6 Committee D19, through a Main Committee ballot, may approve publication of a “Preliminary” Standard Method for a period not to exceed 5 years. Preliminary Standards must contain a minimum of a single-operator precision-and-bias statement and a Quality Control section based on the single operator data. Publication of a Preliminary Standard is conditional on the approval of a full D2777 collaborative study design for the standard. Precision-and-bias statements authorized by this paragraph shall include the date of approval by Committee D19. 1.7 Per Section A21.2.3 of the ASTM Form and Style Manual the committee may delay an interlaboratory study for a new method and include a temporary statement in the Precision and Bias Section that addresses only single operator precision (“repeatability”). This statement is valid for five years from the initial publication date. In this case, a single laboratory study shall be conducted in accordance with 7.6 . 1.8 In Section 12 , this practice shows exemplary precision-and-bias-statement formats for: ( 1 ) test methods yielding a numerical measure, ( 2 ) test methods yielding a non-numerical report of success or failure based on criteria specified in the procedure, and ( 3 ) test methods specifying that procedures in another ASTM test method are to be used with only insignificant modifications. 1.9 All studies, even those exempt from some requirements under previous sections, shall receive approval from the Results Advisor before being conducted (see Section 8 ) and after completion (see Section 13 ). 1.10 This practice satisfies the QC requirements of Practice D5847 . 1.11 It is the intent of this practice that task groups make every effort to retain all the data from their collaborative studies. Values should not be eliminated unless solid evidence exists for their exclusion. The Results Advisor should work closely with the task groups to effect this goal. 1.12 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 Following this practice should result in precision-and-bias statements that can be achieved by any laboratory properly using the test method studied. These precision-and-bias statements provide the basis for generic limits for use in the Quality Control section of the test method. Optionally, the detection and quantitation values provide estimates of the level at which most laboratories should be able to achieve confident detection and meet the minimum precision (expressed as relative standard deviation) expected. 5.2 The method specifies the matrices for which the test method is appropriate. The collaborative test corroborates the write-up within the limitations of the test design. An extensive test can only use representative matrices so that universal applicability cannot be implied from the results. 5.3 The fundamental assumption of the collaborative study is that the matrices tested, the concentrations tested, and the participating laboratories are a representative and fair evaluation of the scope and applicability of the test method as written.