The best replacement for barometer is manometer.

The best alternatives to barometer are rated as following:
★★★★★  manometer
★★★★  thermometer
★★  mercury manometer
★★  altimeter
★  air pressure
★  aneroid barometer
★  barograph
★  mercury barometer
  hygrometer
  aneroid
  water barometer

Your alternative for barometer is not listed? Suggest!
Speaking about barometer, one probably shouldn't forget about tide clock.

Other search terms related to barometer and their ratings are:
★★★★★ tide clock
★★★ water instead of mercury
★ altimeter
You have in mind a companion for barometer and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of barometer in all years. Click on graph for more.
barometer
manometer
thermometer