ISO 4259-4:2021 石油和相关产品 测量方法和结果的精度 第4部分：使用统计控制图验证单个实验室标准试验方法执行的“统计控制”状态
标准编号：ISO 4259-4:2021
中文名称：石油和相关产品 测量方法和结果的精度 第4部分：使用统计控制图验证单个实验室标准试验方法执行的“统计控制”状态
英文名称：Petroleum and related products — Precision of measurement methods and results — Part 4: Use of statistical control charts to validate 'in-statistical-control' status for the execution of a standard te
发布日期：2021-12
标准范围
本文件规定了构建、操作和维护统计控制图的过程和方法，以评估实验室执行标准测试方法是否在统计控制范围内，以及如何建立和验证“在统计控制范围内”状态。它规定了最适合ISO/TC的控制图？28测试方法，其中主要的共同原因变异与长期、多个操作员条件相关。为确定统计内控制而指定的控制图有:个体（I）、移动范围为2（MR2），以及指数加权移动平均（EWMA）或基于区域的运行规则【类似于Western Electric（WE）运行规则【3】】，作为支持I图的灵敏度增强策略。本文件中的程序主要是针对从石油和相关产品的均质来源制备的对照样品的测试获得的数值结果而设计的，其方式如下:保持对照样品之间感兴趣性质的同质性。如果测试方法允许，使用经认证的参考材料（CRM）样品作为对照样品，前提是样品组成代表被测试的材料并且不是纯化合物；如果这样做了，那么实验室最好为CRM样本建立自己的平均值。本文档适用于（已知）随时间稳定的感兴趣属性，以及具有足够分辨率以支持验证数据分布可以由正态（高斯）模型近似表示的假设的数据集。对于假设无法验证的情况，建议了缓解策略。
This document specifies the process and methodology for the construction, operation, and maintenance of statistical control charts to assess if a laboratory's execution of a standard test method is in-statistical-control and how to establish and validate the 'in-statistical-control' status.It specifies control charts that are most appropriate for ISO/TC 28 test methods where the dominant common cause variation is associated with the long term, multiple operator conditions. The control charts specified for determination of in-statistical-control are: individual (I), moving range of 2 (MR2), and either the exponentially weighted moving average (EWMA) or zone-based run rules [similar to Western Electric (WE) run rules[3]] as sensitivity enhancement strategy to support the I-chart.The procedures in this document have been primarily designed for numerical results obtained from testing of control samples prepared from a homogenous source of petroleum and related products in a manner that preserves the homogeneity of properties of interest between control samples. If the test method permits, a certified reference material (CRM) sample is used as a control sample provided the sample composition is representative of the material being tested and is not a pure compound; if this is done then the laboratory best establishes its own mean for the CRM sample.This document is applicable to properties of interest that are (known to be) stable over time, and for data sets with sufficient resolution to support validation of the assumption that the data distribution can be approximately represented by the normal (Gaussian) model. Mitigating strategies are suggested for situations where the assumption cannot be validated.
标准预览图
