变量检查抽样程序. 第2部分: 按验收质量限制 (AQL) 检索且用于独立质量特征逐批检验的单一抽样计划的一般规范

[中文适用范围]： ISO 3951 的这一部分主要设计用于在以下条件下使用： a) 检验程序适用于由一个生产商使用一个生产流程供应的一系列连续批次离散产品。 如果有不同的生产商或生产工艺，则ISO 3951的本部分应分别适用于每个生产商或生产工艺； b) 产品的质量特性可以连续测量； c) 测量误差可以忽略不计（即标准偏差不超过相应过程标准偏差的10%）。 然而，第 9 条和附录 P 中还提供了当测量误差具有不可忽略的标准偏差时适应测量误差的程序； d) 产量稳定（在统计控制下）并且质量特性的分布至少接近正态分布； [外文原描述]： ISO 3951-2:2013 specifies an acceptance sampling system of single sampling plans for inspection by variables. It is indexed in terms of the acceptance quality limit (AQL) and is of a technical nature, aimed at users who are already familiar with sampling by variables or who have complicated requirements. (A more introductory treatment is given in ISO 3951-1.) The objectives of the methods laid down in ISO 3951-2:2013 are to ensure that lots of an acceptable quality have a high probability of acceptance and that the probability of not accepting inferior lots is as high as practicable. This is achieved by means of the switching rules, which provide the following: automatic protection to the consumer (by means of a switch to tightened inspection or discontinuation of sampling inspection) should a deterioration in quality be detected; an incentive (at the discretion of the responsible authority) to reduce inspection costs (by means of a switch to a smaller sample size) should consistently good quality be achieved. In ISO 3951-2:2013, the acceptability of a lot is either implicitly or explicitly determined from an estimate of the percentage of nonconforming items in the process, based on a random sample of items from the lot. ISO 3951-2:2013 is intended for application to a continuing series of lots of discrete products all supplied by one producer using one production process. If there are different producers or production processes, ISO 3951-2:2013 is applied to each one separately.