What is atmospheric pressure measured?
What is atmospheric pressure The weight of the air column extending from the sea surface to the end of the atmosphere is known as atmospheric pressure. The atmospheric pressure varies from one region to another depending on the temperature difference caused by the difference in the angle of the fall of the sun. There are several bands in which atmospheric pressure is distributed, such as the range of low tropical pressure, the high atmospheric pressure behind the orbits, the low atmospheric pressure near the polar circles and the high polar pressure.
Atmospheric pressure factors
There are several factors that affect atmospheric pressure, including the amount of water vapor in the air; it is inversely proportional to atmospheric pressure, as well as temperature; the amount of atmospheric pressure decreases with the temperature rise; the relationship between them is inverse, and the last factor is the terrain; Air pressure is measured inversely with sea level rise. Barometric pressure is measured using a Barometric Instrument for measuring atmospheric pressure in meteorological centers to detect changes in air pressure. It is also used to measure altitudes where atmospheric pressure is inversely proportional to altitude; The more you relax Less atmospheric pressure.
Barometric instruments for measuring atmospheric pressure
The barometer was invented by placing a long glass tube filled with mercury in a glass of mercury, reducing the mercury column in the tube. This is due to air pressure on the surface of the liquid in that cup. This is a barometric type called Mercury Barometer ). The metal barometer is less accurate than mercury, but it is more sensitive and easier to carry. It consists of a hollow metal box of air and a pointer to the value of atmospheric pressure. It has several types (Parrograph).
Air pressure measuring units
Barometer is used in many fields, especially the pressure altimeter, one of the barometric types, which measures the height more accurately than the normal barometer. More than one unit is used to measure atmospheric pressure. The bar, millimeter bar, millimeter millimeter unit, mercury meter, mercury marker, And other units such as the TOR unit relative to the world Torchili, the most famous is the (atomosphere) one millimeter mercurial = 760 Atmosfer.
As for the specific use of mercury in the manufacture of the mercury barometer, it is because of the characteristics that distinguish it from other elements; its density is high and its boiling point is very high, it is hard to evaporate during work, its color helps to see it through the glass tube and the cohesion of its atoms is higher than its adhesion strength With glass, unlike water, which prevents error reading during the experiment, and then invented many devices to measure the pressure of different shape and specifications, such as: (manometer) to measure fluid pressure and impedances, as well as pressure clock.
By Aicha Nawfal