ilmanpainemittari

Ilmanpainemittari, also known as a barometer, is an instrument used to measure atmospheric pressure. Atmospheric pressure is the force exerted by the weight of the air in the atmosphere above a given point. This measurement is crucial for meteorology as changes in air pressure can indicate upcoming weather shifts.

There are several types of barometers. The mercury barometer, invented by Evangelista Torricelli in the 17th century, consists of a glass tube filled with mercury, inverted into a dish of mercury. The atmospheric pressure supports a column of mercury in the tube, and the height of this column is directly proportional to the pressure. While accurate, mercury barometers pose health and environmental risks due to the toxicity of mercury.

A more common and safer type is the aneroid barometer. This device uses a small, flexible, sealed metal chamber called an aneroid cell. As atmospheric pressure changes, the cell expands or contracts. This movement is amplified by a system of levers and springs and then translated into a reading on a dial, usually calibrated in units like hectopascals (hPa) or inches of mercury (inHg).

Ilmanpainemittarit are vital tools for weather forecasting. Falling air pressure often signifies approaching storms or low-pressure systems, while rising pressure typically indicates fair weather and the arrival of high-pressure systems. They are used in weather stations, by pilots, sailors, and even in some home weather stations to monitor environmental conditions.