ISO 3951-1:2005 变量检验用取样程序 第1部分：单一质量特性和单一AQL限制用遂批验收用列入验收质量限度（AQL）的单一取样计划用规范

标准编号：ISO 3951-1:2005

中文名称：变量检验用取样程序 第1部分：单一质量特性和单一AQL限制用遂批验收用列入验收质量限度（AQL）的单一取样计划用规范

英文名称：Sampling procedures for inspection by variables — Part 1: Specification for single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a single quality characteristi

发布日期：2005-04

标准范围

ISO 3951-1:20 05规定了单个抽样计划的可接受抽样系统，其中批次的可接受性是根据该批次中项目的随机抽样，根据工艺中不合格项目的百分比估计值隐含地确定的。ISO 3951-1:20 05主要设计用于以下条件:检验程序适用于由一个生产者使用一种生产工艺供应的连续系列离散产品；其中仅考虑这些产品的单个质量特性x，该特性必须在连续尺度上可测量；其中测量误差可忽略不计，即标准偏差不超过工艺标准偏差的10%；其中生产稳定（在统计控制下），并且质量特性x根据正态分布或接近正态分布的近似分布；其中合同或标准定义了规格上限U、规格下限L或两者；当且仅当一个项目的测量质量特性x满足以下不等式中的适当一个时，该项目才合格:x大于或等于L（即不违反质量标准下限）；x小于或等于U（即不违反质量标准上限）；x大于或等于L，x小于或等于U（即既不违反质量标准的下限也不违反上限）。前两个不等式称为具有单规格极限的情况，第三个不等式称为具有双规格极限的情况。如果双质量标准限值适用，ISO 3951-1:20 05假设符合两个质量标准限值对产品的完整性同等重要；在这种情况下，将单个AQL应用于超出两个质量标准限度的产品组合百分比是适当的。这被称为组合控制。

ISO 3951-1:2005 specifies an acceptance sampling system of single sampling plans for inspection by variables, in which the acceptability of a lot is implicitly determined from an estimate of the percentage of nonconforming items in the process, based on a random sample of items from the lot.ISO 3951-1:2005 is primarily designed for application under the following conditions:where the inspection procedure is to be applied to a continuing series of lots of discrete products all supplied by one producer using one production process;where only a single quality characteristic x of these products is taken into consideration, which must be measurable on a continuous scale;where the measurement error is negligible, i.e. with a standard deviation no more than 10% of the process standard deviation;where production is stable (under statistical control) and the quality characteristic x is distributed according to a normal distribution or a close approximation to the normal distribution;where a contract or standard defines an upper specification limit U, a lower specification limit L, or both;an item is qualified as conforming if and only if its measured quality characteristic x satisfies the appropriate one of the following inequalities:x greater than or equal to L (i.e. the lower specification limit is not violated);x less than or equal to U (i.e. the upper specification limit is not violated);x greater than or equal to L and x less than or equal to U (i.e. neither the lower nor the upper specification limit is violated).The first two inequalities are called cases with a single specification limit, and the third a case with double specification limits.If double specification limits apply, it is assumed in ISO 3951-1:2005 that conformance to both specification limits is equally important to the integrity of the product; in such cases it is appropriate to apply a single AQL to the combined percentage of product outside the two specification limits. This is referred to as combined control.

标准预览图