DIN EN 61811-51-2002 机电式有或无继电器.第51部分:空白详细规范:经质量评估的机电式有或无电信继电器.非标准化型和结构 (IEC 61811-51:2002); 德文版本 EN 61811-51:2002
Electromechanical all-or-nothing relays - Part 51: Blank detail specification; Electromechanical all-or-nothing telecom relays of assessed quality; Non-standardized types and construction (IEC 61811-51:2002); German version EN 61811-51:2002