1.1本规程涵盖了通过包含规范中所用试验方法的精度来确定合理规范限值的方法。 1.2以国际单位制表示的数值应视为标准。括号中给出的值仅供参考。 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和健康实践，并确定监管限制的适用性。 ====意义和用途====== 每种测试方法的精度都有限。即使在尽可能均匀的材料上进行尽可能仔细和正确的测试，测试仍会因材料而异。标准差是测试方法中测试结果变化的一种广泛使用的测量方法( σ ). 在ASTM标准测试中，可以在测试的精度和偏差声明中找到测试方法的标准偏差。这个 “ 蓝皮书， ” ASTM标准的形式和样式 ，要求所有测试方法包括精度和偏差声明。练习C 670 练习C 802 为确定这些值提供指导。 如果测试方法的精度较低，且材料规范中未适当考虑测试精度，则由于测试结果的广泛差异，大多数情况下仍可能会拒绝具有正确质量的均匀材料。为了有合理的规范限制，所用测试的精度应适当包括在规范中。 本规程为在合理规范中正确纳入试验方法的精度提供了指南。

1.1 This practice covers a method of determining rational specification limits by inclusion of the precision of the test method used in the specification. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 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 and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== Each test method has a limited precision. Even if a test is performed as carefully and as correctly as possible on a material which is as homogeneous as can be obtained, the test will still vary from one to another. A widely used measure of the variation of the test results from a test method is the standard deviation ( σ ). In an ASTM standard test, the standard deviation of the test method can be found in the Precision and Bias statement for the test. The “ Blue Book, ” Form and Style for ASTM Standards , requires that all test methods include Precision and Bias statements. Practice C 670 and Practice C 802 provide guidance for determination of these values. If the precision of a test method is low and the precision of the test has not been properly considered in a material specification, a uniform material with the right quality may still be rejected most of the time because of the wide variation of the test results. In order to have rational specification limits, the precision of the test used should be properly included in a specification. This practice provides a guideline for proper inclusion of precision of the test method in a rational specification.