IEC 60417C被替代
Graphical Symbols To Be Used On Equipment - Index, Survey And Compilation Of The Single Sheets - Third Supplement
出版：International Electrotechnical Committee
专家解读视频
Earth, clean (noiseless) earth, protective earth, frame or chassis, equipotentiality, omni-directional microphone, bidirectional microphone, unidirectional or cardioid microphone, hydrophone, underwater sound projector, reversible transducer for underwater sound, transformer, clock; time switch; timer, Morse key; electric shaver outlet.
HD 243:1995 - Identical
DIN 24900-23 (1991-08) - Identical
DIN 40101-1 (1991-11) - Identical
JIS T 1006:1992 - Identical
UNE 20557-1:1985 - Identical
BS 6217:1981 - Identical
DIN 32520-4 (1986-08) - Similar
