Celsius (°C) – The Standard Temperature Scale
The Celsius scale, also known as the centigrade scale, is one of the most widely used temperature measurement systems worldwide. Named after the Swedish astronomer Anders Celsius, it is based on the freezing and boiling points of water at standard atmospheric pressure.
History of the Celsius Scale
The Celsius scale was introduced in 1742 by Anders Celsius, who initially defined it in reverse: 0°C as the boiling point and 100°C as the freezing point. This was later reversed to its modern form. The scale was designed to be practical for scientific and meteorological applications.
Usage and Applications
- Weather Forecasting:Used globally in climate and meteorology.
- Medical Applications:Human body temperature is typically around 37°C.
- Cooking and Food Industry:Oven temperatures and food safety guidelines are often in Celsius.
- Scientific Research:Used in laboratories and industries.
Conversion Formulas
- To Fahrenheit: (°C × 9/5) + 32
- To Kelvin: °C + 273.15
- To Rankine: (°C + 273.15) × 9/5
- To Réaumur: °C × 4/5
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