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Temperature Units

International System of Units (SI)

In the international system of units (SI), the units for measuring temperature are the degree of Kelvin and the degree of Celsius.

The Kelvin system was proposed in 1848. The beginning of the scale is absolute zero and is -273.15 degrees Celsius. The founder of the system was the English physicist William Thomson, who was later granted the title of Lord Kelvin of Largs.

Degree of Celsius is named after the Swedish scientist Anders Celsius, who proposed in 1742 a new scale for measuring temperature. In this system, 0 degrees corresponds to the freezing point of water, and 100 degrees corresponds to the boiling point of water.

The scales of Celsius and Kelvin are shifted by 273.15 degrees, and are calculated as follows:

Fahrenheit

Temperature in the US and in some other English-speaking countries is measured in degrees Fahrenheit.

In 1724 the German scientist Gabriel Fahrenheit proposed this scale for measuring temperature. On the Fahrenheit scale, the ice melting point is +32 ° F, and the boiling point of water is +212 ° F.

The formula for conversion from degrees Celsius to Fahrenheit is as follows:

Rankine Scale

The Rankine scale is a temperature scale, named after the Scottish physicist William Rankin.

Used in English-speaking countries for engineering thermodynamic calculations. It starts at absolute zero temperature, and the freezing point of water corresponds to 491.67 ° Ra, the boiling point of water is 671.67 ° Ra. The number of degrees between the points of freezing and boiling of water on the Fahrenheit and Rankin scale is the same and equal to 180.

The formula for the conversion from degrees Celsius to Rankin is as follows:

Reaumur scale

In the Reaumur scale, the freezing and boiling point of water are taken at 0 and 80 degrees, respectively. Proposed in 1730 by R. Reaumur. Currently, almost not used.

The formula for conversion from degrees Celsius to Reaumur is as follows: