A Thermometer is a temperature measuring device. It is one of the basic weather instruments that are widely used for measuring air temperature. To be more precise, Thermometers are instruments that measure atmospheric heat. The atmosphere is basically made of gas which contains different molecules. The entire atmospheric temperature depends on the movement of these molecules. The fastest they move, the hotter they get which in turn increases the temperature of the atmosphere.

There is a huge amount of confusion regarding the invention of Thermometers. Several inventors invented different versions of Thermometers at the same time. Galileo Galilei invented the water thermometer in 1593, in 1709 Daniel Gabriel Fahrenheit invented the alcohol thermometer.

Thermometers should be put in a place where it is safe from direct exposure to solar heat. But it certainly needs exposure to free air flow. The best solution to this is to use the Stevenson Shelter that would protect the Thermometer from sun rays and allow free air circulation.

The most common Thermometer used is known as the “Expansion Thermometer”. These Thermometers are usually placed outside the windows or are used to measure the body temperature when someone has fever. Most of these Thermometers are closed glass tubes that contain alcohol or mercury in a liquid form.

These liquids change positions when they are heated or cooled indicating the present temperature. Mercury or alcohol expands when it is heated and contracts when cooled.

As already stated, Thermometers are one of the basic devices used at most of the meteorological stations for weather forecasting. Mercury is used for determining higher temperature for its accuracy. Alcohol is used for measuring comparatively low temperature as it has a lower freezing point.