standard lamp vs thermionic valve

standard lamp

noun
  • A lamp supported by a tall vertical pole in order that light comes from above those seated in the vicinity. 

thermionic valve

noun
  • An electronic device incorporating electrons from a glowing cathode inside an evacuated glass tube, functioning as a switch, amplifier etc. 

How often have the words standard lamp and thermionic valve occurred in a corpus of books? (source: Google Ngram Viewer )