Rankine scale Rankine scale The Rankine scale () is an absolute scale of thermodynamic temperature named after the Glasgow University engineer and physicist William John Macquorn Rankine, who proposed it in 1859. (The Kelvin scale was first proposed in 1848.) It may be used in engineering systems where heat computations are done using degrees Fahrenheit. The symbol for degrees Rankine is °R (or °Ra if necessary to distinguish it from the Rømer and Réaumur scales). By analogy with kelvin, some authors term the unit "rankine", omitting the degree symbol. Zero on both the Kelvin and Rankine scales is absolute zero, but a
Thermodynamic temperature heat (to avoid logic loop, we should first define entropy through statistical mechanics): For a system in which the entropy "S" is a function "S"("E") of its energy "E", the thermodynamic temperature "T" is therefore given by so that the reciprocal of the thermodynamic temperature is the rate of increase of entropy with energy. Thermodynamic temperature Thermodynamic temperature is the absolute measure of temperature and is one of the principal parameters of thermodynamics. Thermodynamic temperature is defined by the third law of thermodynamics in which the theoretically lowest temperature is the null or zero point. At this point, absolute zero,