Outdoor temperature sensor

A look back

Long before digital sensors found their way into building automation, the outside temperature was measured using purely mechanical or liquid-based measuring systems. Classic bimetal thermometers used the different expansion rates of two metals, while liquid thermometers were based on the temperature-dependent volume change of alcohol or mercury. These measuring principles enabled reliable temperature readings early on and formed the basis for weather-compensated heating controls. Today, these physical effects still form the basis of modern electronic outdoor temperature sensors – only now they are significantly more precise and faster.