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
Kelvin (K) – The Absolute Temperature Scale
The Kelvin scale is the absolute thermodynamic temperature scale, used primarily in scientific and engineering applications. It starts at absolute zero (0 K), the point at which all molecular motion ceases.
History of the Kelvin Scale
The Kelvin scale was developed in 1848 by Lord Kelvin (William Thomson). He proposed an absolute temperature scale where absolute zero (-273.15°C) represents the lowest possible temperature.
Usage and Applications
- Physics and Chemistry:Used in gas laws and thermodynamic calculations.
- Astronomy:Measuring temperatures of stars and celestial bodies.
- Scientific Research:Essential for precision temperature measurements.
Conversion Formulas
- To Celsius: K - 273.15
- To Fahrenheit: (K - 273.15) × 9/5 + 32
- To Rankine: K × 9/5
- To Réaumur: (K - 273.15) × 4/5