1.1本规程涵盖了精度评估指南，并作为实验室间测试程序（ITP）的管理规程，用于评估橡胶制造和炭黑行业中使用的测试方法的精度。本实践使用了基本的单向方差分析实践计算算法 E691 . 虽然在本实践中未评估偏差，但它是理解精度评估的一个基本概念。 1.2本规程适用于试验结果以定量连续变量表示的试验方法。尽管可能会出现例外情况，但通常仅限于在许多实验室中充分开发和常规使用的测试方法。 1.3给出了两种精度评估方法，描述如下: 稳健统计 试图消除或大幅减少异常值影响的程序。 第一个是 一般精度 该程序适用于橡胶制造业的所有试验方法，第二个是一般精度程序的具体变体，指定为 特殊精度 ，这适用于炭黑测试。这两种程序使用相同的均匀水平实验设计和Mandel h 和 k 统计数据以审查精度数据库中的潜在异常值。然而，他们在拒绝不兼容数据值作为异常值的过程中使用了轻微修改。这个 特殊精度 程序针对每个数据库单元或材料实验室组合的复制次数而定。 ====意义和用途====== 测试使用标准测试方法进行，以生成用于商业、技术和科学目的决策的测试数据。因此，特定测试方法的精度是测试方法和决策过程的重要质量特征或优值。 测试方法的精度评估通常通过以下方式进行:( 1. )一些选定的材料组通常与该方法一起使用，以及( 2. )与一组具有测试方法经验的志愿者实验室合作。评估代表了 及时的事件 这些材料和实验室的试验方法。使用稍有不同的材料或甚至在不同时间使用相同实验室的相同材料进行ITP精度评估，可能会产生不同于初始ITP的精度结果。 经验如参考文献所示 (1-4) 其他地方的研究表明，典型ITP的实验室间再现性差几乎总是由于实验室间的偏见。在所有测试中，与参考实验室以及其他实验室相比，某些实验室总是低或高。许多ITP的这一常见结果在本实践中通过使用三个- 第7节所述的step稳健分析程序。 在将特定测试方法的精度结果应用于消费品-生产者产品验收的产品测试时应谨慎。产品验收程序应基于在特定于商业产品和此类测试相关方实验室的特殊程序中获得的精度数据制定。

1.1 This practice covers guidelines for evaluating precision and serves as the governing practice for interlaboratory test programs (ITP) used to evaluate precision for test methods as used in the rubber manufacturing and the carbon black industries. This practice uses the basic one way analysis of variance calculation algorithms of Practice E691 . Although bias is not evaluated in this practice, it is an essential concept in understanding precision evaluation. 1.2 This practice applies to test methods that have test results expressed in terms of a quantitative continuous variable. Although exceptions may occur, it is in general limited to test methods that are fully developed and in routine use in a number of laboratories. 1.3 Two precision evaluation methods are given that are described as robust statistical procedures that attempt to eliminate or substantially decrease the influence of outliers. The first is a General Precision procedure intended for all test methods in the rubber manufacturing industry, and the second is a specific variation of the general precision procedure designated as Special Precision , that applies to carbon black testing. Both of these procedures use the same uniform level experimental design and the Mandel h and k statistics to review the precision database for potential outliers. However, they use slight modifications in the procedure for rejecting incompatible data values as outliers. The Special Precision procedure is specific as to the number of replicates per database cell or material-laboratory combination. ====== Significance And Use ====== Tests are conducted using standard test methods to generate test data that are used to make decisions for commercial, technical, and scientific purposes. It follows that the precision of a particular test method is an important quality characteristic or figure of merit for a test method and a decision process. An evaluation of the precision of a test method is normally conducted with ( 1 ) some selected group of materials as typically used with that method and ( 2 ) with a group of volunteer laboratories that have experience with the test method. The evaluation represents an event in time for the test method for these materials and laboratories. Another ITP precision evaluation with somewhat different materials or even with the same materials with the same laboratories at a different time, may generate precision results that differ from the initial ITP. Experience as indicated in Refs (1-4) and elsewhere has shown that the poor reproducibility among the laboratories of a typical ITP is almost always due to interlaboratory bias. Certain laboratories are always low or high compared to a reference as well as other laboratories in all tests. This usual outcome for many ITPs is addressed in this practice by the use of the three-step robust analysis procedures as described in Section 7. Caution is urged in applying precision results of a particular test method to product testing for consumer-producer product acceptance. Product acceptance procedures should be developed on the basis of precision data obtained in special programs that are specific to the commercial products and to the laboratories of the interested parties for this type of testing.