Bi-metallic Thermometer, Length : 75 Mm To 300 Mm.

The bi-metallic element consists of two strips of different metals, with different thermal expansion coefficients, inseparably joined together. This strip is spirally or helically wound with one end fixed to the body of the thermometer, and the other attached to the axis of a pointer. Measurement of temperature is made with the bi-metallic system inside the temperature sensor. Temperature variation influences the bi-metallic strip such as to rotate the pointer; this rotation is indicated on a dial.