標準號：ISO/TS 21749-2005
中文標準名稱：計量學儀器的測量和不確定性.重復測量和嵌套實驗
英文標準名稱：Measurement and uncertainty for metrological applications - Repeated measurements and nested experiments
標準類型：N04
發布日期：1999/12/31 12:00:00
實施日期：1999/12/31 12:00:00
中國標準分類號：N04
國際標準分類號：17.020
適用范圍：This Technical Specification follows the approach taken in the Guide to the expression of the uncertainty ofmeasurement (GUM) and establishes the basic structure for stating and combining components ofuncertainty. To this basic structure, it adds a statistical framework using the analysis of variance (ANOVA) forestimating individual components, particularly those classified as Type A evaluations of uncertainty, i.e. basedon the use of statistical methods. A short description of Type B evaluations of uncertainty (non-statistical) isincluded for completeness.This Technical Specification covers experimental situations where the components of uncertainty can beestimated from statistical analysis of repeated measurements, instruments, test items or check standards.It provides methods for obtaining uncertainties from single-, two- and three-level nested designs only. Morecomplicated experimental situations where, for example, there is interaction between operator effects andinstrument effects or a cross effect, are not covered.This Technical Specification is not applicable to measurements that cannot be replicated, such as destructivemeasurements or measurements on dynamically varying systems (such as fluid flow, electronic currents ortelecommunications systems). It is not particularly directed to the certification of reference materials(particularly chemical substances) and to calibrations where artefacts are compared using a scheme knownas a “weighing design”. For certification of reference materials, see ISO Guide 35[14].When results from interlaboratory studies can be used, techniques are presented in the companion guideISO/TS 21748 [15]. The main difference between ISO/TS 21748 and this Technical Specification is that theISO/TS 21748 is concerned with reproducibility data (with the inevitable repeatability effects), whereas thisTechnical Specification concentrates on repeatability data and the use of the analysis of variance for itstreatment.This Technical Specification is applicable to a wide variety of measurements, for example, lengths, angles,voltages, resistances, masses and densities.