Gives symbols on semiconductor devices (symbol elements; qualifying symbols particular to semiconductor devices; examples of semiconductor diodes; examples of thyristors; examples of transistors; examples of photo- sensitive and magnetic fields sensitive devices), electron tubes (symbol elements, general; symbol elements mainly applicable to cathode ray-tubes and television camera tubes, symbol elements mainly applicable to microwave tubes; symbol elements applicable to miscellaneous tubes, including mercury arc rectifiers; examples of electronic tubes; examples of cathode-ray tubes; examples of microwave tubes; examples of miscellaneous tubes including mercury arc rectifiers), radiation detectors and electrochemical devices (examples of ionizing radiation detectors; electrochemical devices).