Which instrument measures air pressure?

Which instrument measures air pressure?

• A. Barometer
• B. Rain Gauge
• C. Hygrometer
• D. Pictogram

Answer: (A)

Air pressure is what the atmosphere pushes on everything, and a barometer is the instrument designed to measure that pressure. In a mercury barometer, higher external air pressure pushes more mercury up the tube, while lower pressure lets it fall; modern versions use a sealed, flexible chamber that deforms with pressure changes. This measurement helps meteorologists predict weather, since rising pressure often signals clearer skies and lower pressure can indicate approaching storms. The other options don’t measure air pressure: a rain gauge collects and measures rainfall; a hygrometer gauges humidity; a pictogram is just a visual symbol, not a measuring device.

Air pressure is what the atmosphere pushes on everything, and a barometer is the instrument designed to measure that pressure. In a mercury barometer, higher external air pressure pushes more mercury up the tube, while lower pressure lets it fall; modern versions use a sealed, flexible chamber that deforms with pressure changes. This measurement helps meteorologists predict weather, since rising pressure often signals clearer skies and lower pressure can indicate approaching storms. The other options don’t measure air pressure: a rain gauge collects and measures rainfall; a hygrometer gauges humidity; a pictogram is just a visual symbol, not a measuring device.