Question

What instrument is used to measure air pressure?

Answer 1

Barometer

A barometer measures air pressure. This works either on the action of air or mercury. Barometers working on the action of air are known as the aneroid barometer and that working on the action of mercury are mercury barometers.

1. Barograph is an aneroid barometer. The instrument has small flexible aneroid cell. The instrument creates vacuum so the small changed in air pressure results in expansion or contraction of the cell.
2. The simple clock-like barometer is also aneroid barometer. Small changes in air pressure move the pointer in the clock. The pointer moves in a semicircular motion over a dial to indicate pressure variations.
3. Mercury barometer has a long glass tube filled with mercury turned upside down in a bowl. The variation in height of the mercury inside the tube indicates the changes in surrounding pressure.

Answer

The scientific instrument used to measure air pressure is barometer. The pressure measured is known as barometric pressure.