图示符号 meaning in English

design symbol
graphic symbol
legend to the symbols

Graphic symbols for railroad maps and profiles
铁路线路图与示意图的图示符号
Graphical symbols for clocks
钟表用图示符号
Graphical symbols for chemical proccesses in laboratories ; basic processes
实验室化学处理过程的图示符号.基本工作过程
Intruder alarm systems - terms and symbols - recommendations for symbols for diagrams
擅入者报警系统.第5部分:术语和符号.第2节:图示符号推荐标准
Control technology ; graphical symbols and identifying letters for process control engineering ; representation of details
控制技术.流程控制技术用图示符号和标识字母.详图