INFRARED CAMERAS Research Experience for Teachers Paul Longwell Summer 2004

1. INFRARED CAMERASResearch Experience for TeachersPaul LongwellSummer 2004

2. What does Infrared mean? Infrared is the name given to radiation that has a wavelength just beyond what our eyes can detect.

3. Types of Infrared Very Near IR Near IR Medium IR Far IR Very Far IR Image Courtesy of NASA Image Courtesy of National Infrared

4. What is special about an Infrared Camera?Our eyes use visible wavelengths to create images.An infrared camera is sensitive to wavelengths that are longer. Image courtesy of FLIR Inc.

5. Same Object – Different Images! Infrared Camera Human Eye Image Courtesy of NASA/IPAC

6. Infrared Imaging Begins With Bolometers… Image Courtesy of PSU/EOC Think of bolometers as resistors that are temperature-sensitive.

7. When an object’s infrared radiation strikes a bolometer… Image Courtesy of PSU/EOC Enhanced Image Courtesy of PSU/EOC The resistance of the bolometer changes, and this is detected by a electronic circuit.

8. Bolometer Technology Gets Moo-ving In 1901, S.P. Langley demonstrated that his primitive bolometer could detect a cow that was standing out in a field!

9. Bolometers are not big! Image Courtesy of PSU/EOC Each side of a bolometer is usually 0.005 centimeters wide. A row of 1000 bolometers would cover a distance of only 5 cm!

10. Before being used in cameras, bolometers must first be tested… Image Courtesy of PSU/EOC Sometimes they fail!

11. Each bolometer helps form one pixel of an image… More Pixels = More Bolometers

12. A typical array of bolometers contains 240 rows and 320 columns Measurements from each bolometer must be collected separately

13. Once assembled, the bolometer array can be put in a camera. The lens focuses the image on the bolometer

14. An infrared camera requires an infrared lens! Image Courtesy of PSU/EOC Germanium is used instead of glass: Infrared radiation passes right through, but visible light does not.

15. Need a small IR camera? Image Courtesy of PSU/EOC

16. This is truly a cool camera!This camera’s detector must be kept cold with liquid nitrogen! Image Courtesy of PSU/EOC

17. Cooled Cameras Image Courtesy of PSU/EOC • Are more expensive • Perform better

18. Images Courtesy of PSU/EOC Miniature Uncooled IR Camera Standard Uncooled IR Camera Standard Cooled IR Camera

19. MRTD TestMinimum Resolvable Temperature Difference Image Courtesy of PSU/EOC • An image like this is produced by placing a room-temperature faceplate (w/ slits) over a heated background. • The background temperature is brought closer and closer to the faceplate temperature until the image cannot be clearly seen.

20. Applications: Image Courtesy of PSU/EOC Examine structures behind walls and floors.

21. Applications Light Switch Image Courtesy of PSU/EOC Locate wires behind walls.

22. Applications Image Courtesy of National Infrared Image Courtesy of National Infrared Image Courtesy of National Infrared Analyze electrical systems.

23. Applications Image Courtesy of National Infrared Evaluate home heat loss.

24. Applications Image Courtesy of National Infrared Animal Science

25. Applications Image Courtesy of Infrared1 Image Courtesy of National Infrared Image Courtesy of National Infrared Detect recent activity

26. Thanks! • Penn State University – Applied Research Laboratory (ARL) • Electro-Optics Center, Kittanning PA • Ken Freyfogle • Wendy Gilpin • Chuck Rapach Image Courtesy of SE-IR Corp.