Editing Barometer (section)

{{short description|Scientific instrument used to measure atmospheric pressure}}
{{pp-semi-indef|small=yes}}
{{broader|Pressure measurement}}
{{Use British English|date=January 2020}}
[[File:Dosen-barometer.jpg|thumb|An analog barometer]]

A '''barometer''' is a scientific instrument that is used to measure [[air pressure]] in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within [[surface weather analysis]] to help find surface [[Trough (meteorology)|trough]]s, [[pressure system]]s and [[weather front|frontal boundaries]].

Barometers and [[pressure altimeter]]s (the most basic and common type of altimeter) are essentially the same instrument, but used for different purposes. An altimeter is intended to be used at different levels matching the corresponding [[atmospheric pressure]] to the [[altitude]], while a barometer is kept at the same level and measures subtle pressure changes caused by weather and elements of weather.  The average atmospheric pressure on the Earth's surface varies between 940 and 1040 hPa (mbar). The average atmospheric pressure at sea level is 1013 hPa (mbar).