What is a Barometer

Barometer is a device that can be used to measure the atmospheric pressure of a place. Since weather forecast requires information about the existing pressure conditions in a place to determine the weather in the future period, the role played by a barometer in weather forecast is of utmost importance. The first ever barometer was invented by Evangelica Torricelli in the year 1643 and it made use of water instead of mercury. One would be surprised to know that the length of the tube used in the first ever barometer was 34 foot. However, in the later stages, Torricelli came up with a newer version of the barometer that made use of mercury and used a tube of lesser length.

At present, there are two types of barometers that are used, namely mercury barometer and aneroid barometer. The aneroid barometer is a digital barometer and it provides more accurate measurements of the pressure with the help of barograph. The mercury barometer works on a simple process as mentioned below. Since the condition of vacuum is maintained inside the tube of the barometer, a little change in pressure initiates the movement of the mercury column. When the pressure in the atmosphere increases; the mercury within the tube rises and vice versa.

The use of barometer can be done for a variety of purposes. The newer versions of the barometer can provide data with great precision thereby, making weather prediction relatively easy. A fall in the atmospheric pressure indicates that the weather in the region is unstable, thereby, necessitating measures to avoid the impact of a storm that might be building up. Also, with the help of barometers that are specially designed, one can get to know the change in altitude too. These kinds of barometers are called altimeters. They work on the principle that as the altitude of a place increases, the pressure drops.

The aneroid barometer makes use of a metal diaphragm, which is reduced to a low pressure. Any increase in the pressure, suppresses the diaphragm and decrease causes the diaphragm to expand. The corresponding pressure is shown by a calibrated scale. It would be worth noting here that the term, ‘aneroid’ literally means ‘without fluid’. The provision for graphical representation of the pressure with the help of aneroid barometer makes it best suited for applications where high precision is a must.

However, it goes without saying that the aneroid barometer is more expensive as compared to the mercury barometer. Owing to the numerous purposes served by the barometer, it is an indispensable part of all weather stations.