1.1 本规程涵盖了计算随机样本中包含多少单位的简单方法，以便以指定精度估计大量材料或工艺生产的所有单位的质量度量。本规程将明确指出在随机样本覆盖的时间间隔内，估计某些属性的平均值或生产过程中产生的不合格项的比例所需的样本量。如果过程未处于统计控制状态，则结果对近期（未来）生产没有预测价值。该实践处理了常见情况，即可以认为采样单元表现出单一（整体）可变性来源； 它不处理多层次的可变性来源。 1.2 本标准未规定单位制。本标准中的尺寸量仅作为计算方法的说明。这些示例对所处理的产品或测试方法没有约束力。 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 本规程旨在确定以规定精度估计批次或过程质量测量所需的样本量。 当质量表示为给定物业的平均批次或不符合规定标准的批次分数时，适用本惯例。特性水平通常可作为材料质量的指标。如果是这样，则该特性的平均值或不符合该特性规范的观察值分数的估计值成为该特性的质量度量。本规程旨在确定所需的样本量，以规定的精度估计批次或过程的质量测量值，作为平均值或不符合规定值的分数。

1.1 This practice covers simple methods for calculating how many units to include in a random sample in order to estimate with a specified precision, a measure of quality for all the units of a lot of material, or produced by a process. This practice will clearly indicate the sample size required to estimate the average value of some property or the fraction of nonconforming items produced by a production process during the time interval covered by the random sample. If the process is not in a state of statistical control, the result will not have predictive value for immediate (future) production. The practice treats the common situation where the sampling units can be considered to exhibit a single (overall) source of variability; it does not treat multi-level sources of variability. 1.2 The system of units for this standard is not specified. Dimensional quantities in the standard are presented only as illustrations of calculation methods. The examples are not binding on products or test methods treated. 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 practice is intended for use in determining the sample size required to estimate, with specified precision, a measure of quality of a lot or process. The practice applies when quality is expressed as either the lot average for a given property, or as the lot fraction not conforming to prescribed standards. The level of a characteristic may often be taken as an indication of the quality of a material. If so, an estimate of the average value of that characteristic or of the fraction of the observed values that do not conform to a specification for that characteristic becomes a measure of quality with respect to that characteristic. This practice is intended for use in determining the sample size required to estimate, with specified precision, such a measure of the quality of a lot or process either as an average value or as a fraction not conforming to a specified value.