The Bimetal thermometer employs a bimetal strip in the form of helix, it works on the principle of thermal expansion - two metals having different coefficient of expansions are joined together to form a bimetal.
The resultant expansion of bimetal is proportional to temperature that is sensed. Bimetal dial thermometers are simple in construction, but rugged.
They are used for measurement of temperature in most of the industrial applications. They are offered in the range of (-) 50°C to 500°C. With rigid stem having bottom or back entry. It can also be offered in every angle rotatable construction at 180°