DIN EN 61753-091-2-2013 光纤互连器件和无源元件. 性能标准. 第091-2部分:C类非连接单模有抽头的循环器. 受控环境 (IEC 61753-091-2-2012); 德文版本EN 61753-091-2-2013
Fibre optic interconnecting devices and passive components - Performance standard - Part 091-2: Non-connectorized single-mode fibre optic pigtailed circulators for category C - Controlled environment (IEC 61753-091-2:2012); German version EN 61753-091-2:2