Evangelista Torricelli was born on October 15, 1608, in the Italian city of Faenza, died on 5 October 1647 in Florence. He is the famous Italian physics and mathematics scientist known for his experiments on open air pressure.
He drew attention to his childhood curiosity about mathematics. In 1627 he went to Rome and worked with Benedetto Castelli, the founder of Hydraulics Science and the demand of Galilei. He began correspondence with Galilei in 1641. The same year, on the recommendation of Castelli, Galileo invited Torricelli to Tuscany. A few weeks after meeting with Galileo, when Galilei died, he transferred Torricelli, the great Duke of Tuscany, to his office. In 1644 he published a book on Geometry and Mechanics. In this book, which fills an important gap in the field of mathematics, the first work of Galileo's mechanics, the common gravity centers of interconnected bodies, move downwards, while the principle of sudden movements can be He was connecting.
Instead of water, Torricelli had the wisdom to put the chick (liquid Mine), which was heavier than thirteen and a half times, so the height of the column was shortened equally. So Torricelli performed the first barometer; One end is clogged and a glass pipe filled with mercury. This pipe is turned upside down, and the open end is dipped in a bathtub filled with mercury again. Some of the mercury in the tube flows into the bathtub and the Mercury column descends up to 760 millimeters in the pipe. Then the weight of mercury is equivalent to atmospheric pressure. As a result of the experiments with mercury-filled tubes, the pressure at sea level was 1033 gr/cm ². In geometry and mechanics, no one cared about their ideas first. Torricelli also tried to develop his mentor, Galileo's telescope and his own microscope.
1643 Torricelli has now invented the device called the Mercury Barometer to measure the air pressure.
At the same time, Blaise Pascal thought of using the barometer to measure the elevation. Since the weight of the atmosphere determines the height of the mercury inside the pipe, this height will be reduced on top of a mountain; At the top of the mountain, the height of the air layer is less than the sea level and the weight will be less. Accordingly, the height of the Mercury column indicates which elevation we are in: This is the essence of altimeter (elevation gauge).
Later, the changes in the atmosphere, reducing the weight of the atmosphere and replicating the height of the Mercury column was understood. Thus, the prediction of air change was learned by looking at the barometer markers; Accordingly, at sea level, mercury at a height of 760 millimeters is a sign of "beautiful weather". Atmospheric pressure can also be measured by mine barometers, which are air-drained cans.
How does it work?
The increased air pressure moves the mercury column and provides elevation to the left arm. Meanwhile, the mercury level in the right arm decreases. The weight that is very little light floats over mercury and rises with it. The rope and reel, depending on weight and counterweight, works like a pulley rig and they may move together. As the air pressure rises, the balance deteriorates and the mercury increases, the lower the air pressure, the higher the balance and the lower the mercury level. This makes a clear and precise measurement.
Bar Barometer
The operating principle of the bar barometer is very simple. The air pressure applied to the right reservoir is the highest pressure on the sea level and the fluid level in the left arm increases. The gap in the left arm must be a vacuum. If there is a gas, the pressure rises and it starts pushing. This causes the measurement to appear below the actual value.
Aneroid Barometer
The vacuum capsule carries a ' B ' movement with slight progress with the ' a ' air pressure change. A small lever, ' c ', strengthens this movement and transmits it to the ' e ' reel through the small chain 'd '. The ' F ' positioned on the reel shows the most accurate result thanks to the indicator bar and ' g ' stabilizer.