Opened 9 years ago

Closed 8 years ago

# Réaumur temperature scale

### Description

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]"

### comment:1 Changed 8 years ago by 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:

• fC(x) = x - 273.15
• fC-1(x) = x + 273.15

and thus With:

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

did I get this about right?

### comment:2 Changed 8 years ago by Gunther Schadow

Milestone: → Version 2.0 set to Gunther Schadow

### comment:3 Changed 8 years ago by Gunther Schadow

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

1. 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): fF(x) = x - 459.67 rather than fF(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.

### comment:4 Changed 8 years ago by 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.

### comment:5 Changed 8 years ago by Gunther Schadow

Resolution: → spam new → closed

Done: [16412]

### comment:6 Changed 8 years ago by Gunther Schadow

Resolution: spam closed → reopened

Text missing.

### comment:7 Changed 8 years ago by Gunther Schadow

Resolution: → spam reopened → closed

### comment:8 Changed 8 years ago by Gunther Schadow

Resolution: spam closed → reopened

### comment:9 Changed 8 years ago by Gunther Schadow

Resolution: → fixed reopened → closed
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