tachometer vs ticker

tachometer

noun
  • A device for measuring or indicating velocity or speed, as of blood, a river, a machine, etc. 

  • A device for measuring the revolutions per minute (RPMs) of a revolving shaft, as with the driveshaft of an automobile. 

ticker

noun
  • A measuring or reporting device, particularly one which makes a ticking sound as the measured events occur. 

  • A watch (timepiece). 

  • A heart, especially a human one. 

  • One who makes a tick mark. 

  • A birdwatcher who aims to see (and tick off on a list) as many bird species as possible. 

  • A ticker tape, either the traditional paper kind or a scrolling message on a screen. 

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