Degree symbol copy from here
Celsius refers to the Celsius temperature scale (in centigrade). Grade Celsius (symbol: ° C ) refers to a temperature expressed on the Celsius scale. The degree Celsius, which is a derivative term, refers to the unit used to indicate a temperature range on the Celsius thermometric scale.
The name “Celsius” comes from the name of the Swedish astronomer Anders Celsius, who first proposed this scale in 1742, two years before his death.
|Celsius to Kelvin formula|
K =°C+ 273.15
Click here to See – Kelvin to degree Celsius.
Until 1954 the temperature of 0 ° C on the Celsius scale was defined as the melting point of ice and that of 100 ° C as the boiling point of water at normal pressure, approximate definition, still used in schools. Currently, the unit “grade Celsius” and the scale Celsius is defined, according to international conventions, by two points: absolute zero and the triple point of water. Absolute zero – the temperature at which nothing can be colder and at which there is essentially no energy in the form of heat – is defined as exactly 0 K and −273.15 ° C. The triple point of water is defined to be exactly 273.16 K and 0.01 ° C.
- sets the size of both degrees, Celsius and Kelvin, to be exactly 1 / 273.16 parts of the interval between the triple point of water and absolute zero;
- establishes that a Kelvin is exactly the same size as a degree on the Celsius scale; and
- establishes that the difference between the zero points between the two stairs is exactly 273.15 Kelvin’s.
In 1742 Anders Celsius proposed an “inverse” scale for the modern Celsius staircase, where 0 was the boiling temperature and 100 was the freezing water. He found that the freezing temperature of the water is not practically dependent on the pressure. He also determined with remarkable accuracy how the boiling temperature of water depends on atmospheric pressure. Due to the high influence of the pressure on the boiling water temperature, he proposed that the zero point (the boiling point of the water) be set at the barometric pressure at sea level, that is, at normal pressure. In 1954 Resolution 4 of the 10th General Conference on Measures and Weights has established that at an international level the normal pressure has 101325 Pascal.
In 1744, the year of Anders Celsius’s death, botanist Carl Linne reversed the Celsius ladder, giving it its current form. In the next 204 years, specialists in thermodynamics called this scale “the centigrade scale”. The temperatures on the centigrade scale were simply called “degrees”, or more precisely “degrees centigrade’s”. The symbol of these degrees was ° C (in different forms over time). Because the term “centigrade” was also the name of the unit of measurement of angles (on the scale of 100 for a right angle – the world system) and had the same connotation in other languages, it was renounced for its use for temperatures, the current term being “degrees Celsius”.
Temperatures and intervals
The degree of Celsius is the equivalent of kelvin when expressing temperatures on the Celsius scale. The effect of defining the Celsius staircase based on the triple point of the standard water and the absolute zero point is that the stairs are no longer defined by the freezing and boiling points of the water. Due to the fact that the standard water was defined later and that its triple point is slightly different from 0.01 ° C, the exact mathematical ratio of 373.16 / 273.16 results in a boiling temperature of only 99.9839 ° C (373.1339 K).
The difference of 16.1 millikelvin (thousandths of degree Celsius) is insignificant for the technical applications because due to the variation of the atmospheric pressure with the height a difference of 1 millikelvin is obtained for a variation of the height of only 0.28 m.
Except the United States of America the Celsius scale is widely used in all countries (see SI ). Everyone in the scientific world (including the US) uses the Celsius scale. In many of the US technical fields, especially the high tech ones, the Celsius scale is used. Apart from the US, the only states that have not adopted the Celsius scale and continue to work with the Fahrenheit grades are Bahamas, Belize, and Palau.
The word “degrees” can be abbreviated as “grade”. As a result, the expression degrees Celsius: may have the following forms: singular / (plural)
- degree Celsius / (degree Celsius)
- GRD Celsius / (same)
- city C / grade C
- grad C / (same)
- ° C / (I go)
As with most unit symbols, as well as all-temperature units, space must be placed between the numeric value and the ° C symbol; for example: “23 ° C.”Only the angle symbol is placed immediately after the numeric value, without an intermediate space; for example: “90 ° angle”.
The special Unicode symbol of °C
Unicode, which is an industry-standard designed to allow the consistent representation in computers of all symbols in the writings used worldwide, assigns the “symbol C” to U + 2103. Pages WWW symbol °C will use the sequence: ℃. Its appearance is the same as that obtained by joining components (°) and (C). Because some computers have trouble displaying the ° C symbol, the combination (°) and (C) can be used instead.