A barometer is an instrument used to measure the atmospheric pressure in an environment. The pressure of the atmosphere is helpful in forecasting the changes in the weather of a region. As the air pressure changes with the altitude, the barometer can also be used to calculate height above the...
Differentialmanometers differential manometer, Torricellian barometer, and siphonFigure 1: Schematic representations of (A) a differential manometer, (B) a Torricellian barometer, and (C) a siphon. Instruments for comparing pressures are called differential manometers, and the simplest such instrument ...
A barometer for measuring the pressure of the atmosphere in absolute terms is simply a manometer in which p2 is made zero, or as close to zero as is feasible. The barometer invented in the 17th century by the Italian physicist and mathematician Evangelista Torricelli, and still in use today,...