Rankine_scale

Rankine scale

For the idealized thermodynamic cycle for a steam engine, see Rankine cycle. For the scale measuring recovery after stroke, see modified Rankin scale.

**Rankine temperature conversion formulae**
	from Rankine	to Rankine
Celsius	[°C] = ([°R] − 491.67) × ⁵⁄₉	[°R] = ([°C] + 273.15) × ⁹⁄₅
Fahrenheit	[°F] = [°R] − 459.67	[°R] = [°F] + 459.67
Kelvin	[K] = [°R] × ⁵⁄₉	[°R] = [K] × ⁹⁄₅
For temperature intervals rather than specific temperatures, 1 °R = 1 °F = ⁵⁄₉ °C = ⁵⁄₉ K Comparisons among various temperature scales

Rankine is a thermodynamic (absolute) temperature scale named after the Scottish engineer and physicist William John Macquorn Rankine, who proposed it in 1859.

The symbol is R (or Ra if to distinguish it from the Rømer and Réaumur scales). As with the Kelvin scale (symbol: K), zero on the Rankine scale is absolute zero, but the Rankine degree is defined as equal to one degree Fahrenheit, rather than the one degree Celsius used by the Kelvin scale. A temperature of
-459.67 °F is exactly equal to 0 R.

A few engineering fields in the U.S. measure thermodynamic temperature using the Rankine scale. However, throughout the scientific world where measurements are made in SI units, thermodynamic temperature is measured in Kelvin.

Some key temperatures relating the Rankine scale to other temperature scales are shown in the table below.

	Kelvin	Celsius	Fahrenheit	Rankine
Absolute zero (by definition)	0 K	−273.15 °C	−459.67 °F	0 R
Freezing point of water¹	273.15 K	0 °C	32 °F	491.67 R
Triple point of water (by definition)	273.16 K	0.01 °C	32.018 °F	491.688 R
Boiling point of water²	373.1339 K	99.9839 °C	211.9710 °F	671.641 R

This standards- or measurement-related article is a stub. You can help Wikipedia by expanding it.

References

^ The ice point of purified water has been measured to be 0.000089(10) degrees Celsius - see Magnum, B.W. (June 1995). "Reproducibility of the Temperature of the Ice Point in Routine Measurements" (PDF). Nist Technical Note 1411, http://www.cstl.nist.gov/div836/836.05/papers/magnum95icept.pdf. Retrieved on 11 February 2007.
^ For Vienna Standard Mean Ocean Water at one standard atmosphere (101.325 kPa) when calibrated solely per the two-point definition of thermodynamic temperature. Older definitions of the Celsius scale once defined the boiling point of water under one standard atmosphere as being precisely 100 °C. However, the current definition results in a boiling point that is actually 16.1 mK less. For more about the actual boiling point of water, see VSMOW in temperature measurement.

References

See also