Temperature ? a term that we use almost daily as a matter of course, without being made aware of the physical correlations. But how may be the term temperature defined?
Everybody perceives temperature in their environment purely subjectively. If we have been too warm or too cold, it is a feeling, which might be different from individual to individual ? because not everyone gets cold at the same speed. The word temperature ? or, better, the condition, that influences (among other activities) our state of mind ? is discussed daily when we are discussing the expected temperature from the elements forecast with friends, acquaintances or colleagues.
Temperature
With the term temperature (from the Greek ? Indulgent ? = warm), a specific thermal state of a body is described. Heat is really a measure of the power of a body, that is generated by the random motion of its atoms or molecules in the body?s interior. Here, the temperature may be the magnitude of a state which establishes the energy content connected with other physical quantities (mass, heat capacity).
Temperature unit
The unit of temperature may be the Kelvin. At a temperature of 0 K, all atoms or molecules inside a body are in rest ? all motion in the body is frozen. One describes this state because the absolute zero point. The Celsius temperature scale which is more common in our latitudes defines the zero point as the freezing point of water, since this condition could be reproduced without great technical effort in past times.
Temperature measurement
Different physical properties are directly influenced by the temperature and thus are employed for temperature measurement, such as, for example:
the dependence of expansion on temperature
the change in electrical resistance with temperature
voltage generation according to the temperature
temperature-dependent frequency fluctuations
changes in the wavelength of rays of a body, with respect to the temperature
Note
Info on our temperature measuring instruments are available on the WIKA Website.g