Thermometer

Thermometers serve for measuring the temperature. The characterization of the devices is based upon the measuring medium. Liquid thermometers make use of the temperature-dependent expansion properties of the liquids as alcohol or mercury. The movement of the liquid within a tube indicate the temperature on the scale. Metal thermometers work with a bimetallic strip. At one end of the bimetallic strip is fixed in the thermometer and then arranged as a spiral. According to the changes in temperature the bimetallic strips bends/straightens due to the different length expansion of the two metals moving the indicator of the temperature scale. Resistance thermometers are based on the principle of interdependence of the factors current flow and resistance of the electric conductor that in turn is influenced by the temperature.