1. Determining the Dew Point
Tariq Khan
study48@hotmail.com

2. Unit Goal
Weather
Dew Point Temperature Relative Humidity
•Integrate concepts of Dew Point, Temperature and Relative Humidity
•Relate Dew Point to Temperature and Relative Humidity
•Integrate into Weather Module
•Key Idea: The closer the Temperature to RH the lower the Dew Point

3. Inquiry based Experimental Design
Hypothesis Experiment Results
• Have students • Does the • Enter Data into
create experiment Excel
experiment measure the Dew • Plot the Graph
based on point? • Analyze results
concepts • Teacher • Compare findings
• Discuss demonstrates with other
experiment then let students groups
design with run experiment
classmates • Have students
think about their
observations

4. Setting up the Experiment
The Following Apparatus is required to conduct the Experiment:
•Regular Drinking Glass
•Temperature Probe
•Ice Cubes
•Glass of Water
•Access to computer (for Excel and Data Probe Recording)

5. Find the Dew Point
•The temperature probe will show decreasing temperature in its logging activity screen
•Have the students touch the glass and observe the glass for formation of dew
•The students should note the temperature at which dew forms

6. Data collection
Dew Point
5:22:34 PM
5:21:50 PM
5:21:07 PM
5:20:24 PM
5:19:41 PM
5:18:58 PM
17
14
23.56
22.81
22.31
21.81
20.81
19.75
19.06
18.75
18.06
16.63
16.13
15.19
15.06
14.44
13.63
13.13
12.63
Time
•X-axis indicates the Temperature
•Y-axis indicates passage of Time
•Dew Point is reached at 12.63
•The left column indicates the temperature while the right indicates the time
•Sample of the data collected through the probe, the Dew Point is indicated by the last
temperature recording.

7. Analysis and Interpretation
Students receive handout with following questions:
• Were the results what you expected them to be?
• How did adding ice cubes to the water affect the
temperature of the water?
• What is the time your Dew Point was reached? What was
the temperature?
• How would you describe the results based on your data?
• Create a graph based on your data, do you see a pattern?
• Would you change anything about the way the experiment
was conducted? Any ideas for further research?

8. Integrating Ideas
Dew Point
Relative
Temperature
Humidity

9. Independent Inquiry
Students will look up the following topics:
• Relative Humidity
• Temperature
Relate lab to classroom activity:
• Students will define the relationship between
Relative Humidity, Temperature and the Dew
Point

10. Incorporating Technology
Students with exceptionalities or difficulty
integrating complex ideas can be given a follow
up activity
The Dew Point calculator integrates all the ideas
in our lab activity and lesson planning
http://www.dpcalc.org/

11. Conclusion
Learning Objectives:
• Concepts Learned: Dew
Point, Temperature, Relative Humidity
• Use of Technology: Data Probe, Excel, Data
Logging software, website
(http://www.dpcalc.org)
• Inquiry based Learning: Students develop the
idea for the lab, compare ideas with
peers, analyze and interpret results

12. Video Presentation
Please click on the picture above to be taken to
the YouTube video presentation demonstrating
the lesson activity described