Sensors designed on the principle of metal expansion
The metal develops a corresponding extension when the ambient temperature changes, so the sensor can signal this response in different ways.
Bimetallic Disc Sensor
The bimetal is composed of two pieces of metal with different expansion coefficients attached together. As the temperature changes, the material A expands to a higher degree than the other metal, causing the metal sheet to bend. The curvature of the bend can be converted into an output signal.
Bimetal Rod and Metal Tube Sensors
As the temperature increases, the length of the metal tube (Material A) increases, but the length of the non-expanding steel rod (Metal B) does not increase, so that the linear expansion of the metal tube can be transferred due to the change of position. In turn, this linear expansion can be converted into an output signal.
Sensors designed for deformation curves of liquids and gases
When the temperature changes, the liquid and gas will also have a corresponding change in volume.
Various types of structures can convert this change in expansion into a change in position, thus producing a change in position output (potentiometer, sense bias, baffle, etc.).
