Liquid thermometers based on the principle of changing the volume of liquid which is poured into the thermometer (usually a mercury or alcohol), when the ambient temperature changes.In connection with the prohibition of the use of mercury in many areas of activity is the search for alternative fillings for household thermometers. For example, such replacement may become galinstan alloy.

Thermometers of this type operate on the same principle as the liquid, but are usually used as sensors .

The work of electric thermometers is based on the change of resistance of the conductor when the temperature changes.

Optical thermometers can detect the temperature by changing the luminance level, and other parameters of the spectrum with temperature.

The infrared thermometer can measure temperature without direct contact with the person. In some countries, this kind of thermometers are used not only in hospitals but also in everyday life.

Technical thermometers liquid used in enterprises in agriculture, petrochemical, chemical, mining, metallurgy, mechanical engineering, housing and communal services, transport, construction, medicine, the word in all spheres of life.