Celsius is a type of thermometer scale used to measure temperature. This scale is used to measure body temperature, air temperature, and temperature in used refrigeration vans, amongst others.
In the Celsius scale, 0 degree typically represents the freezing point of water, and 100 degrees represents the boiling point. It is this 100–degree interval (0° to 100°) that earned it the alias, Centigrade scale – a term that was generally used for about 200 years after its introduction in 1742.
The Celsius scale is used everywhere around the world except in the United States, Belize, Liberia, the Cayman Islands, and the Bahamas. The U.S. uses the Fahrenheit temperature scale. Most scientists in the U.S., however, use Celsius for ease of understanding when sharing data between countries.
A brief history of the Celsius scale
Anders Celsius, a Swedish astronomer, created a temperature scale in 1742 where 0 represented the boiling point of water and 100 the freezing point. Having performed a series of experiments, the astronomer came to the conclusion in his paper “Observations of two persistent degrees on a thermometer,” that the freezing point of water is unaffected by latitude or atmospheric pressure, but that these same variables do affect the boiling point of water. He passed away in 1744.
Around that same time, Swedish botanist Carl Linnaeus independently developed a similar temperature scale but the reverse of what Celsius proposed. This scale had the freezing point at 0° and the boiling point at 100°. Many other physicists, instrument makers, and scientists went on to independently develop this same scale; among them were Daniel Ekstrom, Marten Stromer, and Pehr Elvius.
To honour Anders Celsius, this temperature scale was then named after him, and that is why it is called the Celsius scale today.
There are relatively few countries that still use Fahrenheit as the standard measuring temperature scale. Celsius has received global acceptability and usage since the 1970s. This is particularly because many people considered the scientific methods of Celsius more precise and easier to use than Fahrenheit.
Celsius is widely used by scientists for scientific calculations and projections, and this could also be because a Celsius degree is the same size as that of a Kelvin degree – another popular scale most scientists use. This makes it easier to work with calculations that use Kelvin.
In refrigeration transport of food products and other temperature sensitive goods, the use of the Celsius thermometer is widespread. Refrigeration vans convey goods at certain prescribed temperature range to ensure preservation. The refrigeration van operator controls the temperature in Celsius to meet the requirements of the goods being transported.
Differences/similarities between Kelvin, Celsius, and Fahrenheit
Celsius and Kelvin are very similar in nature – both having the same magnitude. The only noticeable differences are that C is used to denote a unit of Celsius and K used for Kelvin, and 0 K translates to ‘absolute zero’ and 0 °C is the freezing point of water.
The differences between Celsius and Fahrenheit are more significant:
- The Celsius temperature scale is denoted by the °C sign and is named after Anders Celsius (mid-1700s) who did not directly devise the Celsius scale used today. A unit of Fahrenheit, on the other hand, is denoted by the degree °F and is named after Daniel Gabriel Fahrenheit in 1724.
- Both measurement scales are used to measure temperature, however, the methodology involved is different. While Celsius adopts the concept that water freezes at 0 °C and boils at 100 °C, Fahrenheit uses the concept that the freezing point is at 32 °F and below and boiling point is at 212 °F and above.
- In using the Celsius scale, the average human body temperature is measured at 37 °C and in Fahrenheit is 98.6 °F.
- Celsius scale is widely accepted and used in most countries of the world. Fahrenheit is only used in the U.S. and a few other countries.
Facts about Celsius
- Celsius is so far the only unit that includes a capital letter in its full name, unlike the other two prominent temperature measurement units whose letters are all in lowercase. Prior to 1967, kelvin used to be referred to as Kelvin.
- The International Bureau of Weights and Measures (BIPM) has a general rule regarding documenting Celsius values. This rule maintains that the numerical value always precedes the unit and that a space is to be used to separate the unit from the number. For instance, 25 degrees Celsius should read 25 °C not 25° C or 25°C, and definitely not 25°c.
- Most new refrigeration vans use the Celsius scale to measure the temperature inside the vehicle. This is obviously because it is a globally accepted scale, except for a few countries.
- From the 19th century, scientists globally used the term centigrade scale to refer to the Celsius scale, but this brought about confusion as centigrade was the term used to describe a unit of angular movement in both the Spanish and French languages, and there were very similar relationships in other languages too. This led to the International Committee for Weights and Measures (CIPM) to adopt the degree Celsius in 1948.
- Despite this accepted departure from the use of centigrade in place of Celsius, it was not until 1985 that the weather forecasts presented by the BBC switched to Celsius.
If you come across one of these scales either in a refrigeration vehicle, a science project, or on a weather newscast and are having trouble converting them. Here’s a simple formula:
Celsius to Fahrenheit
A unit of Celsius can be converted to Fahrenheit by multiplying it by 9, dividing it by 5 and then add 32.
Fahrenheit to Celsius
Start by subtracting 32, multiplying the result by 5, and then dividing by 9.
Celsius to Kelvin and vice versa
To convert to Kelvin subtract 273 from the unit in Celsius, and to convert from Kelvin to Celsius add 273.
The Celsius temperature scale continues to feature prominently as the most widely used thermometer scale in the world with Kelvin not far behind, and Fahrenheit miles away. This trend is set to continue for a long time to come except if something better is introduced.