Which instrument measures atmospheric pressure?

Which instrument measures atmospheric pressure?

• A. Barometer
• B. Thermometer
• C. Hygrometer
• D. Anemometer

Answer: (A)

Atmospheric pressure is the weight of the air pressing down on the atmosphere and surface. Measuring this pressure helps forecast weather, since rising and falling pressure indicate different weather patterns. The instrument that directly measures this force is the barometer. It can be a mercury or aneroid type: a mercury barometer uses a column of liquid that rises or falls with changes in air pressure, while an aneroid barometer uses a sealed metal chamber that expands or contracts as pressure changes. In contrast, a thermometer measures temperature, a hygrometer measures humidity, and an anemometer measures wind speed. Because only a barometer directly tracks atmospheric pressure, it’s the right choice.

Atmospheric pressure is the weight of the air pressing down on the atmosphere and surface. Measuring this pressure helps forecast weather, since rising and falling pressure indicate different weather patterns. The instrument that directly measures this force is the barometer. It can be a mercury or aneroid type: a mercury barometer uses a column of liquid that rises or falls with changes in air pressure, while an aneroid barometer uses a sealed metal chamber that expands or contracts as pressure changes.

In contrast, a thermometer measures temperature, a hygrometer measures humidity, and an anemometer measures wind speed. Because only a barometer directly tracks atmospheric pressure, it’s the right choice.