Temperature Conversion Reference Page
How Keen Is Your Rank?

Author

DOFPro group

  • Video links go directly to the YouTube video.
  • JTF (Just the Facts) videos are the streamlined versions: greenscreen LaTeX equations, clean graphics, minimal narrative. Think efficient and to the point. Each has a companion TFS video.
  • TFS (The Full Story) videos include interviews, additional explanation, and equations written on whiteboards. Same math, more context, more personality. Each has a matching JTF version.
  • Info Page links lead to definitions, expanded explanations, and related material—because sometimes you really do need to explain it.
  • Visuals links contain the greenscreen or whiteboard materials used in the video, for those who like to see the scaffolding.
  • Wondering about the titles? See Appendix B: If you have to explain it, it’s no longer funny.
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Purpose of Temperature Conversion

Temperature is one of the most commonly measured and reported quantities in chemical and thermal processes. The concept of temperature is fundamental to modeling, designing, and monitoring those processes.

These videos present the four common temperature scales—Kelvin, Celsius, Fahrenheit, and Rankine—and explain how to convert both temperatures and temperature intervals among them.

The title is a pun on the least well-known of the four scales, the Rankine scale. The Wikipedia article on Rankine will provide you with much more information than you probably wanted.

How Keen Is Your Rank? Just the Facts

The Just the Facts video explains the difference between temperature and temperature interval, presents the conversions among the four scales for both, and then works through two examples.

Visuals, Conversion Table

How Keen Is Your Rank? The Full Story

The Full Story video examines common conceptions and misconceptions about temperatures and temperature intervals, compares the four scales, shows how the conversions are derived, lists the conversions, and then works through two examples.

Visuals, Conversion Table

Conversion Tables

Temperatures

Convert From \(\rightarrow\) Kelvin (\(\mathrm{K}\)) Celsius (\(\mathrm{^\circ C}\)) Fahrenheit (\(\mathrm{^\circ F}\)) Rankine (\(\mathrm{^\circ R}\))
TO \(\downarrow\)
\(\mathrm{K}\) N/A \(T(\mathrm{K}) = T(\mathrm{^\circ C}) + 273.15\) \(T(\mathrm{K}) = \frac{5}{9}[T(\mathrm{^\circ F}) - 32] + 273.15\) \(T(\mathrm{K}) = \frac{5}{9} T(\mathrm{^\circ R})\)
\(\mathrm{^\circ C}\) \(T(\mathrm{^\circ C}) = T(\mathrm{K}) - 273.15\) N/A \(T(\mathrm{^\circ C}) = \frac{5}{9}[T(\mathrm{^\circ F}) - 32]\) \(T(\mathrm{^\circ C}) = \frac{5}{9}[T(\mathrm{^\circ R}) - 491.67]\)
\(\mathrm{^\circ F}\) \(T(\mathrm{^\circ F}) = \frac{9}{5} T(\mathrm{K}) - 459.67\) \(T(\mathrm{^\circ F}) = \frac{9}{5} T(\mathrm{^\circ C}) + 32\) N/A \(T(\mathrm{^\circ F}) = T(\mathrm{^\circ R}) - 459.67\)
\(\mathrm{^\circ R}\) \(T(\mathrm{^\circ R}) = \frac{9}{5} T(\mathrm{K})\) \(T(\mathrm{^\circ R}) = \frac{9}{5} T(\mathrm{^\circ C}) + 491.67\) \(T(\mathrm{^\circ R}) = T(\mathrm{^\circ F}) + 459.67\) N/A

Temperature Intervals

Convert From \(\rightarrow\) \(\Delta T\) Kelvin (\(\mathrm{K}\)) \(\Delta T\) Celsius (\(\mathrm{^\circ C}\)) \(\Delta T\) Fahrenheit (\(\mathrm{^\circ F}\)) \(\Delta T\) Rankine (\(\mathrm{^\circ R}\))
TO \(\downarrow\)
\(\Delta T\ (\mathrm{K})\) N/A equal \(\Delta T(\mathrm{K}) = \frac{5}{9} \Delta T(\mathrm{^\circ F})\) \(\Delta T(\mathrm{K}) = \frac{5}{9} \Delta T(\mathrm{^\circ R})\)
\(\Delta T\ (\mathrm{^\circ C})\) equal N/A \(\Delta T(\mathrm{^\circ C}) = \frac{5}{9} \Delta T(\mathrm{^\circ F})\) \(\Delta T(\mathrm{^\circ C}) = \frac{5}{9} \Delta T(\mathrm{^\circ R})\)
\(\Delta T\ (\mathrm{^\circ F})\) \(\Delta T(\mathrm{^\circ F}) = \frac{9}{5} \Delta T(\mathrm{K})\) \(\Delta T(\mathrm{^\circ F}) = \frac{9}{5} \Delta T(\mathrm{^\circ C})\) N/A equal
\(\Delta T\ (\mathrm{^\circ R})\) \(\Delta T(\mathrm{^\circ R}) = \frac{9}{5} \Delta T(\mathrm{K})\) \(\Delta T(\mathrm{^\circ R}) = \frac{9}{5} \Delta T(\mathrm{^\circ C})\) equal N/A

Is It Hot in Here, or Is It Just My Thermistor?

This video introduces common methods of measuring temperature in engineering systems, with particular emphasis on thermistors and the practical interpretation of temperature measurements.

Visuals

Definitions

Temperature
A thermodynamic property related to the tendency of heat to flow from one system to another. At the microscopic level, it is related to the average kinetic energy of molecular motion.
Absolute Zero
The zero point of an absolute temperature scale and the lowest possible thermodynamic temperature.
Absolute Temperature Scale
A temperature scale whose zero point is absolute zero.
Kelvin
The SI absolute temperature scale, named after Lord Kelvin, a British mathematician, physicist, and engineer.
Celsius
A commonly used SI-based temperature scale, named after Anders Celsius, a Swedish astronomer.
Fahrenheit
A commonly used temperature scale in American engineering practice, named after Daniel Gabriel Fahrenheit.
Rankine
The absolute temperature scale used with American Engineering units, named after William John Macquorn Rankine, a Scottish mathematician and physicist.
Ideal Gas Law
For gases at sufficiently low pressure and high temperature, the relationship among absolute temperature \(T\), absolute pressure \(P\), volume \(V\), and number of moles \(n\) is often written as

\[PV = nRT\]

where \(R\) is the universal gas constant. It can also be written as

\[P\hat{V} = RT\]

where \(\hat{V} = V/n\) is the molar volume.

Heat Capacity
The amount of heat required to raise the temperature of a specified amount of a substance by one degree. The two most common forms are the heat capacity at constant pressure, \(C_p\), and at constant volume, \(C_v\).