IEC 61300-3-39:2011选择非成角度物理接触（PC）光学连接器插头用作回波损耗RL测量中的参考插头，并定义用于插头验收测试的验收回波损耗值RLa。当两个插头在随机配对时相对于参考连接器成功测试时，本程序用于保证一定的回波损耗值RL。IEC 61300-3-39的第二版取消并取代了1997年出版的第一版，构成了技术修订。与上一版相比的变化是标准的结构、一般描述和附件。

IEC 61300-3-39:2011 selects non-angled physical contact (PC) optical connector plugs for use as the reference plug in the return loss RL measurement and to define an acceptance return loss value RL_a for use in plug acceptance testing. This procedure is for use to guarantee a certain return loss value RL when two plugs have been successfully tested against the reference connector when randomly mated. This second edition of IEC 61300-3-39 cancels and replaces the first edition published in 1997 and constitutes a technical revision. Changes from the previous edition are structure of the standard, general description and the Annex.