Celsius | notes


  1. ^ According to The Oxford English Dictionary (OED), the term "Celsius' thermometer" had been used at least as early as 1797. Further, the term "The Celsius or Centigrade thermometer" was again used in reference to a particular type of thermometer at least as early as 1850. The OED also cites this 1928 reporting of a temperature: "My altitude was about 5,800 metres, the temperature was 28° Celsius." However, dictionaries seek to find the earliest use of a word or term and are not a useful resource as regards to the terminology used throughout the history of science. According to several writings of Dr. Terry Quinn CBE FRS, Director of the BIPM (1988–2004), including "Temperature Scales from the early days of thermometry to the 21st century" (PDF).  (146 KiB) as well as Temperature (2nd Edition/1990/Academic Press/0125696817), the term Celsius in connection with the centigrade scale was not used whatsoever by the scientific or thermometry communities until after the CIPM and CGPM adopted the term in 1948. The BIPM was not even aware that "degree Celsius" was in sporadic, non-scientific use before that time. It is also noteworthy that the twelve-volume, 1933 edition of OED didn't even have a listing for the word Celsius (but did have listings for both centigrade and centesimal in the context of temperature measurement). The 1948 adoption of Celsius accomplished three objectives:
    1.    All common temperature scales would have their units named after someone closely associated with them; namely, Kelvin, Celsius, Fahrenheit, Réaumur and Rankine.
    2.    Notwithstanding the important contribution of Linnaeus who gave the Celsius scale its modern form, Celsius' name was the obvious choice because it began with the letter C. Thus, the symbol °C that for centuries had been used in association with the name centigrade could continue to be used and would simultaneously inherit an intuitive association with the new name.
    3.    The new name eliminated the ambiguity of the term "centigrade", freeing it to refer exclusively to the French-language name for the unit of angular measurement.
  2. ^ For Vienna Standard Mean Ocean Water at one standard atmosphere (101.325 kPa) when calibrated solely per the two-point definition of thermodynamic temperature. Older definitions of the Celsius scale once defined the boiling point of water under one standard atmosphere as being precisely 100 °C. However, the current definition results in a boiling point that is actually 16.1 mK less. For more about the actual boiling point of water, see VSMOW in temperature measurement. There is a different approximation using ITS-90 which approximates the temperature to 99.974 °C
  3. ^ In 1948, Resolution 7 of the 9th CGPM stated, "To indicate a temperature interval or difference, rather than a temperature, the word 'degree' in full, or the abbreviation 'deg' must be used." This resolution was abrogated in 1967/1968 by Resolution 3 of the 13th CGPM which stated that ["The names "degree Kelvin" and "degree", the symbols "°K" and "deg" and the rules for their use given in Resolution 7 of the 9th CGPM (1948),] ...and the designation of the unit to express an interval or a difference of temperatures are abrogated, but the usages which derive from these decisions remain permissible for the time being." Consequently, there is now wide freedom in usage regarding how to indicate a temperature interval. The most important thing is that one's intention must be clear and the basic rule of the SI must be followed; namely that the unit name or its symbol must not be relied upon to indicate the nature of the quantity. Thus, if a temperature interval is, say, 10 K or 10 °C (which may be written 10 kelvin or 10 degrees Celsius), it must be unambiguous through obvious context or explicit statement that the quantity is an interval. Rules governing the expressing of temperatures and intervals are covered in the BIPM's "SI Brochure, 8th edition" (PDF).  (1.39 MiB).
Other Languages
Afrikaans: Celsius
aragonés: Grau Celsius
asturianu: Grau Celsius
azərbaycanca: Selsi şkalası
Bân-lâm-gú: Liap-sī
беларуская: Градус Цэльсія
беларуская (тарашкевіца)‎: Градус Цэльсія
български: Градус Целзий
བོད་ཡིག: སེ་དྲོད།
bosanski: Stepen Celzija
brezhoneg: Derez Celsius
català: Grau Celsius
čeština: Stupeň Celsia
dansk: Celsius
Deutsch: Grad Celsius
español: Grado Celsius
Esperanto: Grado celsia
euskara: Celsius gradu
فارسی: سلسیوس
føroyskt: Celsiusstigin
français: Degré Celsius
Frysk: Celsius
galego: Celsius
贛語: 攝氏
한국어: 섭씨
हिन्दी: सेल्सियस
hrvatski: Celzij
Bahasa Indonesia: Celsius
interlingua: Celsius
íslenska: Selsíus
italiano: Grado Celsius
ქართული: ცელსიუსი
Kiswahili: Selsiasi
latviešu: Celsija grāds
Lëtzebuergesch: Grad Celsius
lietuvių: Celsijus
Limburgs: Celsiussjaol
la .lojban.: jacke'o
македонски: Целзиусов степен
മലയാളം: സെൽഷ്യസ്
मराठी: सेल्सियस
Bahasa Melayu: Celsius
Mirandés: Grau Celsius
Nederlands: Celsius
Nedersaksies: Celsius
Nordfriisk: Graad Celsius
norsk nynorsk: Celsius
occitan: Gra Celsius
ਪੰਜਾਬੀ: ਸੈਲਸੀਅਸ
پنجابی: سیلسیس
Patois: Selsios
Plattdüütsch: Grad Celsius
português: Grau Celsius
română: Celsius
Scots: Celsius
shqip: Celcius
sicilianu: Gradu cintigradu
Simple English: Celsius
slovenčina: Stupeň Celzia
српски / srpski: Степен целзијуса
srpskohrvatski / српскохрватски: Celzijus
Basa Sunda: Celsius
svenska: Grad Celsius
తెలుగు: సెల్సియస్
Türkçe: Celsius
українська: Градус Цельсія
اردو: سیلسیس
Tiếng Việt: Độ Celsius
West-Vlams: Celsius
Winaray: Sentigrado
吴语: 摄氏温标
粵語: 攝氏
中文: 摄氏温标