Réaumur temperature scale

[Gunther Schadow]

There is also the Réaumur scale:

"The Réaumur scale (°Ré, °Re, °R), also known as the "octogesimal division",[1] is a temperature scale in which the freezing and boiling points of water are set to 0 and 80 degrees respectively. The scale is named after René Antoine Ferchault de Réaumur, who first proposed something similar in 1730.[2]

The Réaumur scale saw widespread use in Europe, particularly in France and Germany as well as Russia, as referenced in works of Dostoyevsky, Tolstoy, and Nabokov.[4][5][6] By the 1790s, France chose the Celsius scale for the metric system over the Réaumur measurements.[2] Its only modern use is in the measuring of milk temperature in cheese production. It is used in some Italian dairies making Parmigiano-Reggiano and Grana Padano cheeses and in Swiss Alp cheeses.[7]"

[Gunther Schadow]

0 [degRe] = 0 Cel 80 [degRe] = 100 Cel

(0.8 [degRe] - 0 [degRe]) = 1 K

degree Celsius	temperature	°C	Cel	CEL	yes	•	cel(1 K)
degree Fahrenheit	temperature	°F	[degF]	[DEGF]	no	•	degf(5 K/9)
degree Rankine	temperature	°R	[degR]	[degR]	no	5	K/9
degree Réaumur	temperature	°Re	[degRe]	[degRe]	no	•	cel(1 K)

With:

• f_C(x) = x - 273.15
• f_C^-1(x) = x + 273.15

and thus With:

• f_Re(x) = ( x - 273.15 ) * 0.8
• f_Re^-1(x) = x / 0.8 + 273.15

did I get this about right?

[Gunther Schadow]

Need to check the Fahrenheit conversion definition as well, as #54 complains:

5. The first conversion function from the function pair "degf(5 K/9)" as declared in "ucum-essence.xml" seems to have the following definition (due to the scale factor in the declaration of the function): f_F(x) = x - 459.67 rather than f_F(x) = 9/5 x - 459.67. Or should "degf(5 K/9)" be "degf(1 K)"?

I doubt that this is an error, but a misunderstanding. Still need to check.

[Gunther Schadow]

It is not an error, because we say the function pair degf(5 K/9) is defined as fF(x) = 9/5 x - 459.67, the function pair's name is "degf(5 K/9) with all these numbers.

[Gunther Schadow]

Done: [16412]

[Gunther Schadow]

Text missing.