ISO/IEC指南98-3:20 08是1995年版《测量不确定度表示指南》(GUM)的再版，略有修正。本指南建立了评估和表达测量不确定度的一般规则，可在不同精度水平和许多领域（从车间到基础研究）遵循。本指南的原则旨在适用于广泛的测量，包括以下所需的测量: 维持生产中的质量控制和质量保证； 遵守和执行法律法规； 进行科学和工程领域的基础研究和应用研究与开发； 校准标准和仪器，并在整个国家测量系统中进行测试，以实现对国家标准的可追溯性； 开发、维护和比较国际和国家物理参考标准，包括参考材料。

ISO/IEC Guide 98-3:2008 is a reissue of the 1995 version of the Guide to the Expression of Uncertainty in Measurement (GUM), with minor corrections. This Guide establishes general rules for evaluating and expressing uncertainty in measurement that can be followed at various levels of accuracy and in many fields — from the shop floor to fundamental research. The principles of this Guide are intended to be applicable to a broad spectrum of measurements, including those required for:

• maintaining quality control and quality assurance in production;
• complying with and enforcing laws and regulations;
• conducting basic research, and applied research and development, in science and engineering;
• calibrating standards and instruments and performing tests throughout a national measurement system in order to achieve traceability to national standards;
• developing, maintaining, and comparing international and national physical reference standards, including reference materials.