THERMOGRAPHY

1. THERMOGRAPHY BY :SOHIT KUMAR CHAUHAN

2. THE BASICS • NEAR INFRARED • MID INFRARED • THERMAL INFRARED

3. ATOMS • TWO ENERGY ORBITALS • LOW ENERGY ORBITAL • HIGH ENERGY ORBITAL • ELECTRON MOVES TO HIGHER ORBIT • WHEN COMES BACK RELEASES ENERGY AS PHOTON

4. THERMAL ENERGY • Thermal images, or Thermograms, are actually visual displays of the amount of infrared energy emitted, transmitted, and reflected by an object. • Incident Energy = Emitted Energy + Transmitted Energy + Reflected Energy • Second law of thermodynamics and Emissivity

5. RADIATIVE HEAT EXCHANGE

6. EMISSIVITY • Emissivity is a term representing a material's ability to emit thermal radiation

7. THERMAL IMAGING SYSTEM

8. INFRARED TEMPERATURE MEASUREMENT

9. MODERN INFRARED THERMOMETER

10. Planck's Equation shows, the peak energy shifts towards shorter wavelengths as the temperature increases.

11. TWO COLOR THERMOMETRY

12. TYPES OF INFRARED DETECTORS UNCOOLED INFRARED DETECTOR COOLED INFRARED DETECTOR Use sensors with operating range from 4k to just below room temperature. The cooling is necessary for the operation of the semiconductor materials used. Use sensors that work by catching IR radiations. • Use a sensor operating at ambient temperature. • Cooling is not necessary. • Use sensors that work by the change of resistance, voltage or current when heated by infrared radiation.

13. UNCOOLED INFRARED DETECTOR COOLED INFRARED DETECTOR Require cryogenic coolers for cooling. They are expensive both to produce and to run. Materials used for cooled infrared detection are indium antimonide indium arsenide mercury cadmium telluride lead sulfide lead selenide • Do not require bulky, expensive cryogenic coolers • They are smaller and less costly. • Materials used for uncooled infrared detection are • vanadium(V) oxide • lanthanum barium manganite • amorphous silicon • lead zirconate titanate(PZT) • Lanthanum doped lead zirconate titanate

14. ADVANTAGES • It shows a visual picture • It is capable of catching moving targets in real time • It is able to find deteriorating • It can be used to measure or observe in areas inaccessible or hazardous for other methods • It is a non-destructive test method • It can be used to find defects • It can be used to detect objects in dark areas

15. DISADVANTAGES • high price range • Images can be difficult to interpret accurately when based upon certain objects • Accurate temperature measurements are hindered by differing emissivities and reflections from other surfaces • Most cameras have ±2% accuracy or worse • Only able to directly detect surface temperatures

16. APPLICATIONS • Condition monitoring • Digital infrared thermal imaging in health care • Thermology • Veterinary Thermal Imaging • Night vision • Research • Process control • Nondestructive testing • Surveillance in security, law enforcement and defence • Chemical imaging • Volcanology • Building

17. Condition monitoring

18. In health care

19. Process control Steel Ladle Manufacturing

20. Veterinary Thermal Imaging

21. Defence

22. Surveillance in security

23. REFERENCES • Rogalski A. and Chrzanowski K. 2002, “Infrared Devices and Techniques”, Contributed Paper: Opto-electronics Review • Darling, Charles R.; "Pyrometry. A Practical Treatise on the Measurement of High Temperatures." Published by E.&F.N. Spon Ltd. London. 1911 • www.wikipedia. org • www.howstuffworks.com

24. THANK YOU QUERIES