光纤传感器 第1-4部分：应变测量 基于瑞利散射的分布式传感

[中文适用范围]： IEC 61757-1-4:2025规定了基于单模光纤中瑞利背向散射特征光谱相关性分析的分布式光纤传感器的术语、结构和测量方法，用于绝对应变测量，其中光纤在约10米到数十公里的测量范围内作为分布式应变测量元件。本文件同样适用于结合布里渊和瑞利背向散射效应优势的混合传感器系统，以获得最佳测量质量。本文件还规定了这些分布式光纤应变传感器的重要特性和性能参数，并定义了测量这些特性和参数的程序。IEC 61757的本部分不适用于点测量或动态应变测量。使用单模光纤中布里渊散射进行分布式应变测量的内容见IEC 61757-1-2。附录A列出了该应变测量技术的主要应用，附录B则简要描述了其测量原理。 [外文原描述]： IEC 61757-1-4:2025 defines the terminology, structure, and measurement methods of distributed fibre optic sensors for absolute strain measurements based on spectral correlation analysis of Rayleigh backscattering signatures in single-mode fibres, where the fibre is the distributed strain measurement element in a measurement range from about 10 m to tens of km. This document also applies to hybrid sensor systems that combine the advantages of Brillouin and Rayleigh backscattering effects to obtain optimal measurement quality. This document also specifies the most important features and performance parameters of these distributed fibre optic strain sensors defines procedures for measuring these features and parameters. This part of IEC 61757 does not apply to point measurements or to dynamic strain measurements. Distributed strain measurements using Brillouin scattering in single-mode fibres are covered in IEC 61757-1-2. The most relevant applications of this strain measurement technique are listed in Annex A, while Annex B provides a short description of the underlying measurement principle.