Réaumur (°Re) – The Historic Scientific Scale
The Réaumur scale was once widely used in Europe, particularly in France and Germany. It is based on the freezing (0°Re) and boiling (80°Re) points of water.
History of the Réaumur Scale
Created by René Antoine Ferchault de Réaumur in 1731, the scale was primarily used in scientific and industrial applications until it was replaced by the Celsius system.
Usage and Applications
- Historic Applications:Used in 18th-19th century Europe.
- Food Industry:Some cheese-making and confectionery recipes still use Réaumur.
Conversion Formulas
- To Celsius: °Re × 5/4
- To Fahrenheit: (°Re × 9/4) + 32
- To Kelvin: (°Re × 5/4) + 273.15
- To Rankine: (°Re × 9/4) + 491.67
Rankine (°R) – The Engineering Absolute Scale
The Rankine scale is an absolute temperature scale similar to Kelvin but based on Fahrenheit increments. It is used mainly in thermodynamic calculations, particularly in the United States.
History of the Rankine Scale
Developed by William Rankine in 1859, this scale is designed for engineering applications where Fahrenheit is commonly used.
Usage and Applications
- Thermodynamics:Used in heat and energy calculations.
- Engineering:Common in power plants and refrigeration.
Conversion Formulas
- To Celsius: (°R - 491.67) × 5/9
- To Fahrenheit: °R - 459.67
- To Kelvin: °R × 5/9
- To Réaumur: (°R - 491.67) × 4/9