A barometer is used to measure atmospheric pressure.

Quick Scoop: The Basics

When people ask “what is used to measure atmospheric pressure,” the standard scientific instrument is the barometer , and atmospheric pressure is often called barometric pressure for that reason. A barometer senses how much the air above a location is pressing down and turns that invisible push into a readable value, usually in units like hectopascals (hPa), millibars (mbar), or millimeters of mercury (mmHg).

There are two classic types:

  • Mercury barometer – uses a column of mercury in a glass tube; the height of the mercury column changes with air pressure.
  • Aneroid barometer – uses a sealed flexible metal capsule that expands or contracts with pressure changes and moves a pointer on a dial.

In everyday weather reports and aviation, when you hear about “pressure” or “barometric pressure,” the reading behind the scenes is almost always coming from a barometer.

In modern weather stations and smartphones, electronic barometers with silicon pressure sensors do the same job in a compact, digital way, but they are still called barometers because they measure atmospheric pressure.

TL;DR: The instrument used to measure atmospheric pressure is a barometer (mercury, aneroid, or modern electronic versions).

Information gathered from public forums or data available on the internet and portrayed here.