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
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