Changes

The term '''absolute temperature scale''' usually refers to the [[Kelvin]] temperature scale, but can also refer to the [[Rankine]] scale. These scales are based on the conventional scales for measuring temperature - [[Celsius]] in most non-US countries and [[Fahrenheit]] in the [[United States]].

The term '''absolute temperature scale''' usually refers to the [[Kelvin]] temperature scale, but can also refer to the [[Rankine]] scale. These scales are based on the conventional scales for measuring temperature – [[Celsius]] in most non-US countries and [[Fahrenheit]] in the [[United States]].

==Need for an absolute scale==

==Need for an absolute scale==

Chemists and physicists working with [[gas]]es came to the realization that the conventional temperature scales were not adequate for characterizing the effect of temperature on the decrease in [[volume]] and [[pressure]] of gases with the corresponding decrease in the actual temperature of the gases.

Chemists and physicists working with [[gas]]es came to the realization that the conventional temperature scales were not adequate for characterizing the effect of temperature on the decrease in [[volume]] and [[pressure]] of gases with the corresponding decrease in the actual temperature of the gases.

Ultimately, they realized that if they could decrease the temperature of an [[Ideal Gas|ideal gas]] to a point where all [[molecular motion]] ceased, that would be a good "[[absolute zero]]" point. They found that this temperature would be -273.16 °C (-459.6 °F).

Ultimately, they realized that if they could decrease the temperature of an [[Ideal Gas|ideal gas]] to a point where all [[molecular motion]] ceased, that would be a good "[[absolute zero]]" point. They found that this temperature would be -273.15 °C (-459.67 °F).

==Kelvin scale==

==Kelvin scale==

Like the Kelvin scale, the absolute zero temperature on the Rankine scale is at its zero point - 0°R. However, one degree on the Rankine scale is one degree on the Fahrenheit scale.

Like the Kelvin scale, the absolute zero temperature on the Rankine scale is at its zero point - 0°R. However, one degree on the Rankine scale is one degree on the Fahrenheit scale.

Thus, the freezing point of water would be 491.6 °R (32 °F + 459.6), and the boiling point of water would be 671.6 °R (212 °F + 459.6).  

Thus, the freezing point of water would be 491.67 °R (32 °F + 459.67), and the boiling point of water would be 671.67 °R (212 °F + 459.67).  

== References ==

== References ==

[[Category:Units of Temperature]]

[[Category:Units of Temperature]]