Temperature gauge working principle

Answer 1

thermometers filled with either a liquid such as Mercury or an evaporating fluid as used in refrigreators. in both cases the inside of the sensor head and the connecting tube are completely full. any rise in temperature produces expansion or evaporation of the liquid so the sensor becomes pressurised. the pressure is related to the temperature and it may be indicated on a simple pressure gauge.

another well known principle that if two metals are rigidly joined together as a two layer and heated, the difference in the expansion rate causes the strip to bend. the strip is twisted into a long thin coil inside a tube. one end is fixed at the bottom of the tube and the other turns and move a pointer on a dial.

Answer 2

A temperature gauge measures the level of heat energy in a system by sensing the expansion or contraction of a material in response to changes in temperature. This is achieved by a sensor, such as a bimetallic strip, thermocouple, or resistance temperature detector, which converts the temperature change into a readable display on the gauge. The movement of the sensor is typically connected to a pointer or electronic display that indicates the temperature reading.