GB/T 18311.20-2007
ActiveFibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-20: Examinations and measurements - Directivity of fibre optic branching devices
纤维光学互连器件和无源器件 基本试验和测量程序 第3-20部分:检查和测量 纤维光学分路器件的方向性