Absolute Temperature Scales, Rankin, Kelvin

There are two absolute temperature scales used in connection with very low-temperature work such as Cryogenics, see Par. 1-49. These two scales are the Fahrenheit Absolute Scale (FA) and the Centigrade Absolute Scale (CA). The Absolute Zero Fahrenheit (FA) Scale uses the same divisions as the Fahrenheit Scale, however, the zero for this scale is located at 460 deg. below zero Fahrenheit.

Fig. 1-4. A comparison of Fahrenheit, Centigrade, Rankin, and Kelvin thermometer scales. The a-Boiling temperature of the water. B-Standard conditions temperature. C-Freezing of refrigerating temperatures for food. D-Range food cabinet temperatures. E-Range of evaporator temperatures for food. F-Range of frozen food cabinet temperature of the water. G-Absolute 0

The Absolute Zero Centigrade Scale uses the same divisions as the Centigrade Scale which places the zero for the scale 273 deg. below zero Centigrade.
The Absolute Fahrenheit Scale is called the Rankin Scale (R).
The Absolute Centigrade Scale is called the Kelvin Scale (K).
Fig. 1-4 shows a comparison of the Fahrenheit, Centigrade, Rankin, and Kelvin
thermometer scales.

Problem: What is the freezing point and boiling point of water using the Rankin Scale?
Solution: To calculate the freezing point: Water freezes at 32 F.
The Rankin Scale zero is 460 degrees below zero F.
R temperature at which water will freeze is 460 + 32 = 492 R.
The freezing temperature of the water may be expressed as 492 R.
To calculate the boiling point:
Water boils at 212 degrees above zero F.
The boiling point on the Rankin Scale will be:
460 + 212 = 672 R.
The boiling temperature of the water may be expressed as 672 R.

Problem: What is the temperature at which water freezes and boils using the
Kelvin Scale?
Solution: To calculate the freezing point:
Water freezes at zero degrees Centigrade. The Kelvin Scale zero is 273 degrees below zero Centigrade. The freezing temperature of the water is therefore 273 degrees above zero Kelvin
or 273 degrees Kelvin.
The freezing temperature may be expressed as 273 K.
To calculate the boiling point:
Water boils at 100 degrees above zero Centigrade,
The boiling point of water on the Kelvin Scale will be: 100 + 273 = 373 K. Boiling point may be expressed as 373 K.