Concepts

Infrared radiation, temperature, EM spectrum

Overview

The IR camera can see infrared radiation from signalling devices and objects at various temperatures. It can produce IR and visible light composite images, which help identify what is emitting IR (or not emitting IR). The camera enables explorations of transparency and opaqueness to different parts of the EM spectrum through glass and plastic., as well as the relation between IR emissions and temperature.

Details

Equipment

• [1] IR camera with USB cable
• [1] Laptop with Flir Tools software
• [1] Thin plastic bag
• [1] Pane of glass
• [1] Ice water
  

Classroom Assembly

1. Turn on the laptop. It takes a few minutes to reach a usable state.
2. Turn on the IR camera.
   
3. Start the Flir Tools software on the laptop.
4. Connect the IR camera to the laptop using the USB cable.
   
5. Choose the live stream option when it pops up on the laptop.
6. Connect the computer to the projector.
   

Script

Introductory demo:

1. Project the laptop screen to the class.
2. Set the IR camera stream to be full-screen.
   
3. Open the camera shutter.
4. Pan the camera over the class. They should show up as warm blobs.

Transparency/opaqueness demo:

1. Ask for a volunteer.
   
2. The volunteer puts one's hand inside the plastic bag, showing people they cannot see into it with their eyes.
3. Look through the bag with the IR camera. The hand should be clearly visible in IR.
4. Remove the plastic bag.
5. The volunteer holds up one's hand behind the glass, showing people they can see it with their eyes.
6. Look at the glass with the IR camera. The hand's IR signal should not be visible.

There are many objects you can use in a hot/cold demo. Here's an example:

1. Look at your hand with the IR camera. It should look like a warm blob.
2. Put your hand in ice water for a few seconds.
3. Remove your hand from the water and look at it using the IR camera. It should look like a cold blob. You can talk about how IR corresponds to a lot of molecular vibrations, and cooling something reduces the amount of vibration, so it reduces the IR signal too.

When finished, turn off the IR camera.

Additional Resources