GB/T 4728.9-2022电气简图用图形符号第9部分:电信:交换和外围设备国家标准
英文:Graphical symbols for electrical diagrams—Part 9: Telecommunications :Switching and peripheral equipment GB/T 4728.9-...
英文:Graphical symbols for electrical diagrams—Part 9: Telecommunications :Switching and peripheral equipment GB/T 4728.9-...