IEC 60793-1-34:2021作为IEC 60793-1-34:2021 RLV提供，其中包含国际标准及其红线版本，显示了与上一版本相比技术内容的所有变化。IEC 60793-1-34:2021对机械特性制定了统一要求:未涂覆光纤中的光纤卷曲或潜在曲率，即指定长度的光纤已从涂层中剥离。当使用被动对准熔接器或主动对准质量熔接器时，光纤卷曲已被确定为使光纤的熔接损耗最小化的重要参数。两种公认的方法用于测量未涂覆光纤中的光纤卷曲: -方法A:侧视图显微镜； -方法B:激光束散射。 这两种方法都通过确定无支撑纤维端部绕纤维轴线旋转时发生的偏转量来测量未涂覆纤维的曲率半径。方法A使用视觉或数字视频方法来确定光纤的偏转，而方法B使用线传感器来测量一个激光束相对于参考激光束的最大偏转。通过测量光纤绕其轴旋转时的偏转行为并了解测量装置的几何形状，可以根据简单的圆形模型计算光纤的曲率半径，其推导见附录C。两种方法都适用于IEC 60793（所有部分）中描述的B型光纤。方法A是参考测试方法，用于解决争议。这第三版取消并取代了2006年出版的第二版。本版构成技术修订版。与上一版相比，此版本包括以下重大技术变更:-修正激光散射的几个推导方程； -角度增量从10°到30°到10°到45°的变化； -将附件B从资料性改为规范性。

IEC 60793-1-34:2021 is available as IEC 60793-1-34:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 60793-1-34:2021 establishes uniform requirements for the mechanical characteristic: fibre curl or latent curvature in uncoated optical fibres, i.e. a specified length of the fibre has been stripped from coating. Fibre curl has been identified as an important parameter for minimizing the splice loss of optical fibres when using passive alignment fusion splicers or active alignment mass fusion splicers.Two methods are recognized for the measurement of fibre curl, in uncoated optical fibres:
- method A: side view microscopy;
- method B: laser beam scattering.
Both methods measure the radius of curvature of an uncoated fibre by determining the amount of deflection that occurs as an unsupported fibre end is rotated about the fibre's axis. Method A uses visual or digital video methods to determine the deflection of the fibre while method B uses a line sensor to measure the maximum deflection of one laser beam relative to a reference laser beam. By measuring the deflection behaviour of the fibre as it is rotated about its axis and understanding the geometry of the measuring device, the fibre's radius of curvature can be calculated from simple circular models, the derivation of which are given in Annex C. Both methods are applicable to type B optical fibres as described in IEC 60793 (all parts). Method A is the reference test method, used to resolve disputes. This third edition cancels and replaces the second edition published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- modification of several derivation equations for laser scattering;
- change of angular increment from 10° to 30° to 10° to 45°;
- change of Annex B from informative to normative.