Temperature as State - Heat & Thermodynamics Step by Step

Temperature is a state variable. Differences in kelvin measure how far apart two thermal states are.

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Read absolute temperatures

Temperature is a state reading. These thermometers read 300 kelvin and 330 kelvin.

T_{\text{cool}} = 300\ \text{K}\qquad T_{\text{warm}} = 330\ \text{K}

The warmer state is higher by 30 kelvin. The difference is a temperature interval.

\Delta T = 330\ \text{K} - 300\ \text{K} = 30\ \text{K}