Merkurbarómetri

The Merkurbarómetri, often translated as the Mercury Barometer, is an instrument used to measure atmospheric pressure. It was invented by Evangelista Torricelli in 1643. The device consists of a glass tube filled with mercury, inverted into a dish also containing mercury. As the atmospheric pressure outside the dish changes, it pushes down on the mercury in the dish, causing the level of mercury in the inverted tube to rise or fall. The height of the mercury column is then used as an indicator of atmospheric pressure.

The unit of measurement derived from the mercury barometer is the millimeter of mercury (mmHg), also known as Torricelli (Torr). A standard atmospheric pressure at sea level is defined as 760 mmHg. This measurement is crucial in meteorology for forecasting weather patterns. Changes in barometric pressure can indicate the approach of storms or fair weather. For instance, a falling pressure often suggests deteriorating weather, while a rising pressure typically indicates improving conditions.

While mercury barometers were historically the standard for precise pressure measurements, they have largely been replaced by more modern and often safer instruments, such as aneroid barometers. Mercury barometers are susceptible to breakage due to their glass components and the toxicity of mercury itself. Despite this, their historical significance in the development of atmospheric science and their fundamental principle of operation remain important concepts in physics and meteorology education.