elavhõbedabaromeeter

An elavhõbedabaromeeter, also known as a mercury barometer, is a scientific instrument used to measure atmospheric pressure. It was invented by Evangelista Torricelli in 1643. The device consists of a glass tube closed at one end, filled with mercury, and inverted into a dish containing more mercury. The atmospheric pressure acting on the mercury in the dish supports a column of mercury in the tube. The height of this column is directly proportional to the atmospheric pressure. At standard atmospheric pressure at sea level, the mercury column typically rises to about 760 millimeters (29.92 inches). Variations in the height of the mercury column indicate changes in atmospheric pressure, which can be used to forecast weather patterns. Higher pressure generally suggests fair weather, while lower pressure may indicate approaching storms. Mercury barometers are accurate but require careful handling due to the toxicity of mercury. They have largely been replaced by aneroid barometers in many applications due to safety and portability concerns. However, mercury barometers are still used in some scientific and meteorological contexts where high precision is paramount.