Definition of Temperature

1. Definition of Temperature

We are aware of how hot or cold a substance is with our senses.
However, the feelings that we have vary significantly depending on the time and person,

and the range of hotness and coldness is also narrow.

 

Hence, temperature is defined as the objective and

numeric expression of hotness and coldness.

 

As a measure to express states of matter, in statistical mechanics,

temperature can be defined as the measure of the average kinetic energy of the particles in a substance.

 

Temperature is often confused with heat in daily life,

but heat refers to the total amount of energy transferred to or from a substance,

whereas temperature is a measure of the energy possessed by a substance.

 

2. Temperature Scale

There are four temperature scales as follows.

① Celsius scale(℃ ) : On the Celsius scale, the freezing point of water is defined as 0 and its boiling point

as 100 at standard atmospheric pressure and both points are scaled in 100 divisions.

② Kelvin scale(˚K) : On the Kelvin scale, absolute zero is defined as 0 K

and the freezing and boiling points of water are scaled in 100 divisions.

③ Fahrenheit scale(℉ ) : On the Fahrenheit scale, the freezing and boiling points of water at standard atmospheric

pressure are placed in 180 divisions, and the freezing point of water is scaled to 32 degrees Fahrenheit.

④ Rankin scale(˚R) : On the Rankin scale, absolute zero is defined as 0 R

and the freezing and boiling points of water are scaled in 180 divisions.