barómetri

Barómetri is a term derived from the Greek words "baros" meaning weight and "metron" meaning measure. It refers to the scientific instrument used to measure atmospheric pressure, commonly known as a barometer. This measurement is crucial for understanding weather patterns and forecasting.

The invention of the barometer is generally attributed to Evangelista Torricelli in 1643. He created the first mercury barometer, which works by balancing the weight of atmospheric pressure against a column of mercury in a sealed tube. As atmospheric pressure changes, the height of the mercury column rises or falls, indicating higher or lower pressure.

Other types of barometers exist, including aneroid barometers, which do not use mercury. These devices utilize a small, flexible metal box, called an aneroid cell, from which some air has been removed. Changes in atmospheric pressure cause the box to expand or contract, and this movement is amplified and transmitted to a needle on a dial.

Barometric pressure readings are often expressed in units such as millibars (mb), hectopascals (hPa), or inches of mercury (inHg). Standard atmospheric pressure at sea level is approximately 1013.25 millibars or 29.92 inches of mercury. Lower pressure generally indicates unsettled weather, while higher pressure typically signifies clear and stable conditions. Meteorologists use barometric pressure data extensively in their weather models and forecasts.