IEC 60793-1-20:20 14建立了测量无涂层光纤几何特性的统一要求。未涂覆光纤的几何形状直接影响拼接、连接器化和布线，因此是需要仔细规范、质量控制和测量的基本参数。第二版取消并取代了2001年出版的第一版，构成了技术修订。与上一版相比，此版本包括以下重大技术变更: -所有光纤类型的参考测试方法从折射近场方法更改为视频灰度透射近场方法； -所有纤维类型的测试长度现在将在纤维的详细规格中规定； -所有多模光纤类型的芯照明波长现在可以在光纤的详细规范中指定，尽管给出了默认值； -现在将在详细规范中为所有多模光纤类型指定纤芯k因子（决策级别）； -该版本在描述测量时更加具体； -充分描述了数据缩减和转换； -折射近场和透射近场方法的数据缩减方法现在是统一和一致的。 关键词:测量无涂层光纤的几何特性

IEC 60793-1-20:2014 establishes uniform requirements for measuring the geometrical characteristics of uncoated optical fibres. The geometry of uncoated optical fibres directly affect splicing, connectorization and cabling and so are fundamental parameters requiring careful specification, quality control, and thus measurement. This second edition cancels and replaces the first edition, published in 2001, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- the reference test method for all fibre types is changed to the video grey scale transmitted near field method from the refracted near field method;
- the test lengths for all fibre types are now to be specified in the fibre's detail specification;
- the core illumination wavelength for all multimode fibre types may now to be specified in the fibre's detail specification although defaults are given;
- the core k-factor (decision level) is now to be specified in the detail specification for all multimode fibre types;
- this edition is substantially more specific in describing the measurement;
- data reduction and transformation is fully described;
- the data reduction methodology for both refracted near-field and transmitted near-field methods are now unified and consistent. Keywords: measuring the geometrical characteristics of uncoated optical fibres