The barometer comes from the union “baro and gauge” which refers to a tool for measuring atmospheric pressure. The most common way of doing this is using a mercury barometer, which is a very old tool that uses the force per unit area exerted by the weight of the atmosphere, which is the weight of the air acting on the earth, a pressure that is known for “atmospheric pressure” where this prodigy was discovered by the evangelist Torricelli who was an Italian physicist and mathematician.
The mercury barometer is made up of an 850 mm high tube, which contains mercury inside. This tube is made of glass, but its upper end is closed, while its lower end is open. As it is called, the tube is filled with mercury and the order is changed and placed inside a bucket that will also be filled with that same material.
On the other hand, the mercury in the tube descends until it reaches a height of 760 mm almost at the level of the basin, which is called the barometric height. The above is accessed when a vacuum occurs at the top edge of the tube. This vacuum is called a barometric chamber, where finally the atmospheric pressure was given by the variations due to the elevation of mercury after the previous evolution where this variation varies between 737 and 775 mm of elevation.
In the barometer area you can also find other types such as aneroid barometers, fortifications.
Aneroid barometer, it is a barometer that does not use mercury, but also indicates variations in atmospheric pressure due to the more or less large deformations that a metal box with elastic walls causes, which are those that designate the mechanical properties of certain materials.
The barometer pill box consists of a Torricellian tube not fitted with mercury contained in a cylindrical glass cuvette thus assigned by a suede base where its path can be changed by means of a screw that supports the tip of an ivory cone.