atomizer vs sprinkler head

atomizer

noun
  • An instrument for reducing a liquid to spray or vapor for disinfecting, cooling, medical use or perfume spraying. 

sprinkler head

noun
  • A heat-activated device that sprays water in the event of a fire, usually mounted on a ceiling. 

How often have the words atomizer and sprinkler head occurred in a corpus of books? (source: Google Ngram Viewer )