![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Module 1: Basic Concepts - Temperature
Temperature ScalesValue for Standard Temperature
Summary of Equations for Temperature Conversions
Calculator:
Temperature Converter
Objectives
-
Recall which temperature scales are absolute and which are relative.
- Convert from one temperature scale to another.
The absolute temperature scale starts at absolute zero (negligible molecular motion) and has no maximum limit. The absolute temperature and pressure scales are most useful for the scientific and engineering calculations necessary to evaluate gas behavior. For example, gas stream volume calculations are performed using the absolute gas temperature. Many of the calculations in the field of air pollution will require the conversion of relative temperatures to absolute temperatures.
-
#1
-
Which of the following temperature scales are "relative" scales? Select all that apply.
-
Celsius
-
Rankine
-
Fahrenheit
-
Kelvin
-
Celsius
-
#2
-
Which of the following temperature scales are absolute scales? Select all that apply.
-
Celsius
-
Rankine
-
Fahrenheit
-
Kelvin
-
Celsius
We are departing from normal convention by adding a degree symbol to Kelvin. This measure allows us to avoid confusion in many air pollution equations where "K" is used as a constant.
-
#3
-
From Figure 1 [Temperature scales (Kelvin-Celsius)], what do you know about the size of a degree Kelvin compared to a degree Celsius?-
°K < °C
-
°K > °C
-
°K = °C
-
°K < °C
-
#4
-
From Figure 2 [Temperature scales (Rankine-Fahrenheit)], what do you know about the size of a degree Rankine compared to a degree Fahrenheit?-
°R < °F
-
°R > °F
-
°R = °F
-
°R < °F
-
#5
-
From Figure 3 [Temperature scales (Kelvin-Celsius and Rankine-Fahrenheit)], when a gas temperature rises 150°F how much has it risen in degrees Rankine?
So far, we've learned the following:
.gif){kind=small}
.gif){kind=small}
Note: The Greek symbol "
" in the equations means "change in."
-
#6
-
Using Figure 3, can you figure out how to convert from °R to °F ?
- Hint: °R = °F + ?
- Hint: °R = °F + ?
-
#7
-
Using Figure 3, can you figure out how to convert from °K to °C?
- Hint: °K = °C + ?
- Hint: °K = °C + ?
Value for Standard Temperature
When calculations in this course require the use of "standard" temperature, the EPA's standard temperature of 20°C or 68°F will be used.
Summary of Equations
for Temperature Conversions
Conversion of Temperature Changes from One Temperature Scale to Another
.gif)
Conversion of Temperature Magnitudes from Relative to Absolute Temperature Scales
.gif)
Note: For convenience, the values for absolute zero in the Fahrenheit and Celsius scales have been rounded. Actual values for absolute zero in these two scales are -459.67°F and -273.15°C.
Conversions of Temperature Magnitudes from Metric to English Temperature Scales
.gif)
Temperature Converter (Calculator)
|
Purpose: This calculator converts a given temperature to four different scales: Celsius, Fahrenheit, Kelvin, and Rankine.
Restrictions on Use: Output is not valid when values below absolute zero temperature are entered (0°K, 0°R, -273.15°C, and -459.67°F). |
Notes:
-
This Java applet may take a few minutes to load.
-
Sometimes calculator output is provided in an exponential format in base ten as shown below.
5.2e003 = 5.2
103
5.2e-003 = 5.2 10-3
-
Inputting non-numeric characters such as commas and percent signs will result in erroneous output. (Decimal points are fine to use.)
- This calculator may yield slightly different results than making calculations using the equations presented in the text. It uses the more exact values for absolute zero expressed in the two relative scales: -273.15°C and -459.67°F, instead of using the rounded values, -273°C and -460°F.
Practice Problems
Temperature
-
Instructions:
- Complete the Practice Problems before proceeding to the next lesson. Click on the button below.