Thermodynamics: Temperature Scales

## Temperature Scales

The two temperature scales that most people have heard of are the Celsius scale and the Fahrenheit scale. The Celsius scale is the temperature scale that is used to measure temperature in the standard international system of measurement, or SI system. At 0 degrees C water will start to freeze, and at 100 degrees C water will boil. Fahrenheit on the other hand is used to measure temperature in the English system of measurement. For Fahrenheit water will freeze and 32 degrees and will boil at 212 degrees. To relate the two scales to each other the following equation would be used.

(1)

Now, in thermodynamics the thermodynamics scales are used. The thermodynamic scales do not have negative number values, but instead define an absolute zero. At absolute zero there will be no kinetic energy present between molecular bonds. This value has never been reached in real life, but scientists have come close to reaching it. The thermodynamics scales are Kelvin and Rankine. The Kelvin scale is SI thermodynamic scale and can be related to the Celsius scale using the following equation.

(2)

The Rankine scale on the other hand is the English thermodynamic scale. To relate the Fahrenheit scale to the Rankine scale the following equation would be used.

(3)

When solving thermodynamic problems the thermodynamic scales should be used.