Pressure altimeters
Inside the pressure altimeter is tightly closed metal box in the shape of the disk, in which there is a vacuum. The capsule walls are thin and pofalowane respectively so as to make it flexible and up vulnerable to deformation. The external pressure causes the walls of the capsule strain. The higher the external pressure, the deflection is greater. And vice versa. Then, using the leverage ratio, and these small changes are amplified and converted to the movement on the scale tips. The relationship between the increase in pressure and the increase in height is well known, so the pressure scale can be easily translated into the scale height. The pressure at a given height, however, is not always the same, varies depending on climatic conditions.