光纤.第1-54部分:测量方法和试验程序.γ辐射

[中文适用范围]： 本文件概述了一种测量暴露于伽马辐射的光纤和光缆稳态响应的方法。它可用于确定B类单模或A类A1和A2类多模光纤（无论是成缆还是不成缆形式）由于暴露于伽马辐射而产生的辐射诱导衰减水平。 光纤和光缆的衰减在暴露于伽马辐射时通常会增加。这主要是由于放射性电子和空穴在玻璃缺陷位置的捕获（即“色心”的形成）。本测试程序关注两个感兴趣的范围：适用于估计环境背景辐射影响的低剂量率范围，以及适用于估计不利核环境影响的高剂量率范围。环境背景辐射影响的测试采用类似于IEC 60793-1-40方法A（切割法）的衰减测量方法。不利核环境影响的测试通过监测测试样品在暴露于伽马辐射之前、期间和之后的功率来进行。色心通过光（光漂白）或热去填充导致恢复（辐射诱导衰减的减少）。恢复可以在广泛的时间范围内发生，这取决于辐照时间和退火温度。这使得辐射诱导衰减的表征变得复杂，因为衰减取决于许多变量，包括测试环境的温度、样品的配置、施加于样品的总剂量和剂量率以及用于测量的光水平。 本测试不是光纤电缆非光学材料部件的材料测试。如果要研究电缆材料在辐照下的降解，需要使用其他测试方法。 本测试方法的编写包含清晰、简洁的指令列表。进行正确、相关和有意义的辐照测试以及限制测量不确定性所需的背景知识单独在IEC TR 62283中提供。 [外文原描述]： IEC 60793-1-54:2018 RLV contains both the official IEC International Standard and its Redline version. The Redline version is available in English only and provides you with a quick and easy way to compare all the changes between the official IEC Standard and its previous edition. IEC 60793-1-54:2018 outlines a method for measuring the steady state response of optical fibres and optical cables exposed to gamma radiation. It can be employed to determine the level of radiation-induced attenuation produced in Class B single-mode or Class A, category A1 and A2 multimode optical fibres, in either cabled or uncabled form, due to exposure to gamma radiation. The attenuation of cabled and uncabled optical fibres generally increases when exposed to gamma radiation. This is primarily due to the trapping of radiolytic electrons and holes at defect sites in the glass (i.e. the formation of "colour centres"). This test procedure focuses on two regimes of interest: the low dose rate regime suitable for estimating the effect of environmental background radiation, and the high dose rate regime suitable for estimating the effect of adverse nuclear environments. The testing of the effects of environmental background radiation is achieved with an attenuation measurement approach similar to IEC 60793-1-40 method A, cut-back. The effects of adverse nuclear environments are tested by monitoring the power before, during and after exposure of the test sample to gamma radiation. The depopulation of colour centres by light (photo bleaching) or by heat causes recovery (lessening of radiation induced attenuation). Recovery can occur over a wide range of time which depends on the irradiation time and annealing temperature. This complicates the characterization of radiation induced attenuation since the attenuation depends on many variables including the temperature of the test environment, the configuration of the sample, the total dose and the dose rate applied to the sample and the light level used to measure it. This test is not a material test for the non-optical material components of a fibre optic cable. If degradation of cable materials exposed to irradiation is studied, other test methods will be used. This test method is written to contain a clear, concise listing of instructions. The background knowledge that is necessary to perform correct, relevant and expressive irradiation tests as well as to limit measurement uncertainty is presented separately in IEC TR 62283. This third edition cancels and replaces the second edition published in 2012. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - test conditions related to photobleaching have been changed; - the test length has been modified to yield a total induced attenuation in the test sample at the end of the irradiation between 3 dB and 10 dB.