Barometeret

Barometeret, often used as the definite form of the word barometer in some Scandinavian languages, denotes an instrument for measuring atmospheric pressure. Barometers are essential in meteorology, aviation, and navigation, because short- and long-term pressure changes correlate with weather systems.

Barometers originated in the 17th century. Evangelista Torricelli demonstrated the mercury barometer in 1643, using a column of mercury that balanced atmospheric pressure. Over the centuries, mercury barometers became standard for precise measurements, while the invention of the aneroid barometer in the 19th century produced a portable, non-fluid alternative using a sealed metallic chamber.

Operating principle: a mercury barometer relies on the height of a mercury column balancing air pressure; the height is read in millimeters of mercury. An aneroid barometer uses a flexible chamber whose deformation changes a dial on a pointer, often linked to a spring. Modern barometers may use electronic sensors that translate pressure changes into digital readings.

Units and reference: pressure is commonly expressed in millimeters of mercury (mmHg) or hectopascals (hPa). Standard sea-level pressure is about 1013.25 hPa (760 mmHg).

Applications: barometers are used for weather forecasting, calibration of other instruments, and as a reference for altitude measurements in aviation and mountaineering. Today, electronic barometers and digital sensors provide continuous pressure data and are integrated into weather stations, smartphones, and many scientific instruments.

Limitations: readings can be affected by temperature, instrument orientation, and local air flow. Regular calibration and maintenance are important for accuracy, especially in professional meteorological work.