burglar alarm vs smoke detector

burglar alarm

noun
  • The loud warning signal produced by a burglar alarm. 

  • A warning device that is activated by trespassers, intended to deter burglars. 

smoke detector

noun
  • A device that sounds an alarm when it detects smoke or other evidence of fire. 

How often have the words burglar alarm and smoke detector occurred in a corpus of books? (source: Google Ngram Viewer )