IEC 60417C : 1977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.
BS 6217(1981) : 1981 - Identical
DIN 40101-1 : 1991 - Identical
DIN 40100-22 : 84 DRAFT 89 - Corresponds
BS 6217(1981) : 1981 - Identical
DIN 30603 : 1985 - Identical
DIN 32520-4 : 1986 - Similar to
UNE 20557-1 : 1985 - Identical
