Lämpötilahysteresis

Lämpötilahysteresis refers to a phenomenon where the measured temperature of a substance or system depends not only on the current heat flow but also on its past thermal history. This means that reaching a specific temperature might occur at different rates or require different energy inputs depending on whether the system was previously hotter or colder. It is a form of hysteresis, a general term for phenomena where the state of a system depends on its history.

In practical terms, temperature hysteresis can be observed in various contexts. For example, in phase transitions, like the melting or freezing of a substance, the transition temperature might be slightly different when approaching it from a solid state compared to a liquid state. This difference can be due to factors like supercooling or superheating, where the substance remains in a metastable state above or below its equilibrium phase transition temperature.

Another area where temperature hysteresis is relevant is in the calibration of thermometers or temperature sensors. If a sensor has been subjected to a wide range of temperatures, its response might not be linear or immediately revert to its original state when the temperature changes. Understanding and accounting for this hysteresis is crucial for accurate temperature measurements in scientific experiments, industrial processes, and everyday devices. The magnitude of the hysteresis effect is often dependent on the material properties and the rate of temperature change.