Making Sense of Sensors

Student Worksheet:
Design Your Own Hygrometer

You are part of a team of engineers who have been given the challenge of developing an instrument to detect changes in humidity -- a hygrometer. You'll have lots of materials to choose from, and will likely have to incorporate a pivot and gauge within your hygrometer. If your system works, you'll be able to report a change in the humidity in your classroom. How you accomplish the task is up to your team!. 
  
 Planning Stage
Meet as a team and discuss the problem you need to solve. You'll need to determine which materials you'll request from the many everyday items your teacher has available. As a team, come up with your best design and draw it in the box below.  Be sure to indicate the materials you anticipate using, including the quantity you'll request from your teacher. Present your design to the class. You may choose to revise your teams' plan after you receive feedback from class.  

Design:

Materials Needed:

	
 Making Sense of Sensors

Student Worksheet (continued): 

In the box below, draw the scale that you will use to "measure" changes in humidity.  You may use numbers or words in your scale.  You may wish to copy the one you draw to use within your hygrometer, or make another one that fits the size of your instrument during construction.

Scale:                                                                                               Example:

	

 Making Sense of Sensors

Student Worksheet (continued): 

 Construction Phase

Build your hygrometer.  During construction you may decide you need additional items or that your design needs to change.  This is ok -- just make a new sketch and revise your materials list.  You may want to trade items with other teams, or request additional materials from your teacher.

 Testing Phase

Leave your hygrometer overnight to generate a base "reading" of humidity.  The next day, record the "normal" humidity measurement in the box below.

Next, the hygrometers will be exposed to humidity by a series of sprays of mist/water.  Mark your hygrometers "readings" after each spray.

Reading on Hygrometer before exposure to mist	Reading on Hygrometer after exposure to 4 sprays of mist	Reading on Hygrometer after exposure to 8 sprays of mist	Reading on Hygrometer after exposure to 16 sprays of mist	

				

 Evaluation Phase
Teams then complete an evaluation/reflection worksheet, and present their findings to the class.

 Making Sense of Sensors

Student Evaluation Form 

1. Did you succeed in creating a hygrometer that indicated a change in humidity?

2.  What aspect of your design do you think worked best?  Why?

3.  What hygrometer "engineered" by another student team did you find most inspiring?  How did it work better than yours, or what did feature did you appreciate that the other team came up with?

4. Did you decide to revise your original design while in the construction phase?  Why?  How?

5. Hygrometers have been measuring humidity for hundreds of years.  Do you think that technology has improved the hygrometer?  How?

 Making Sense of Sensors

Student Evaluation Form (continued): 

6.  How durable do you think your hygrometer is?  Would it be able to continue to work for a week, two weeks, a year, a decade?  What would you have to do to your hygrometer to make it reliable for a longer period of time?

7.  Do you think you would have been able to complete this project easier if you were working alone?  Explain…

8.  If you could have used a material or materials that were not provided to you, what would you have requested?  Why do you think this material might have helped with the challenge?

9.  Can you identify five sensors in your school building?

10.  What was your favorite part of the challenge?  Design Phase?  Building Phase?  Testing Phase?  Why?