2. CONTENTS
1. INTRODUCTION
2. INFRARED THERMOGRAPHY
3. INFRARED RADIATION
4. IR CAMERA
5. TYPED OF THERMOGRAPHY
1. ACTIVE THERMOGRAPHY
2. PASSIVE THERMOGRAPHY
6. COLOUR REPRESENTATION
7. EXPERIMENTAL SETUP
8. RESULTS
9. OTHER APPLICATIONS
10. ADVANTAGES& DISADVANTAGES
3. INTRODUTION
Infrared thermography(IRT) is the method, which
detects infrared energy emitted from object and
converts it to temperature
The thermal image is produced by means of infrared
camera which detects the infrared radiation
In this, discuss about some application of IRT and the
detection of defects in a concrete specimen
5. INFRARED THERMOGRAPHY
Infrared thermography(IRT) is the method,
which detects infrared energy emitted from
object, converts it to temperature
“IRT” is simply taking pictures of temperatures
A non-contact , image based method to
examine temperature or thermal patterns in
objects
6. INFRARED RADIATION
Infrared radiation (IR), is a region of the
electromagnetic radiation spectrum where
wavelengths range from about 700 nanometers to 1
millimeter
Infrared rays is everywhere, where ever sunlight
reaches (by direct or by scattering)
All objects having heat emits EM radiation as their
7. IR CAMERA
The camera converts radiated heat energy into an
electrical signal and displays the thermal image
Thermal images can be obtained in total darkness
Because the camera only depends upon the temperature
of the object
9. CONT.
The lens is made of germanium , because the glass
doesn’t pass IR waves,it pass only low wavelength
radiations
It has reasonable cost
It has a long distance range
10. TYPES OF THERMOGRAPHY
1. ACTIVE THERMOGRAPHY
The active thermograph is frequently chosen to
examine the inside of a building, using an external
source of IR radiation and these can be gained by
meansof externalheating.
11. 2. PASSIVE THERMOGRAPHY
This method isuseddirectly in the presenceof solar
radiation. It doesn’t require anyexternalof heating.
Its usedto examineexterior of building mainly for the
diagnosis of building
13. EXPERIMENTAL SETUP
A concrete specimen having defects is arranged for this
(0.5x0.5x0.10 m)
The polystyrene defects are in it, two discs and a
rhombus(thickness= 4cm)
The thermal stimulation of the specimen is monitored
14. CONT.
The existence of inhomogeneties, affects the heat
transfer and causes temperature distribution
The active thermography is used here.
As the external source of thermal excitation ,1000 W
halogen lamp is used for 45-60 min
Thermal excitation distance upto 1.5 – 3 meter
15. CONT.
After heating the thermal image is taken
by IR camera
Experimental setup of the thermal excitation, heating distance
of 1.5 m from the specimen surface
16. RESULTS
The inhomogeneties or defects in the specimen
is examined
The temperature distribution in the material is
found
The shape of defect and the position can be
monitored.
17. CONT.
The concrete having different compressive
strengths, the defects can be detected
FIG 1& FIG 2 having M20 &M40 respectively
18. CONT.
Existence of reinforcements affects the possibility of
detecting damage
Defect under dense reinforcements decrease the
possibility of detecting the defect
• Having with and without the reinforcements
19. OTHER APPLICATIONS OF IRT
1. BUILT ENVIRONMENT
a) Measure heat loss
b) Detect hot or cold spot
c) Detect electrical hot spot
d) Examine pipe behind wall
e) Detect source of seepage & moisture presence
etc.
f) Other concrete structure inspections
20. CONT.
Cavities or holes
2. IN BIOLOGICAL
Detect living creatures in poor visibilities
Can be used instead of mammography
Oncology
Neuromuscular diseases
21. CONT.
3. IN SECURITY
Detect camouflaged targets in darkness
Security breach
In fire and rescue
22. CONT.
4. IN NAVIGATION
in car rear camera ,detect heat signatures in blind
spot
Search and rescue operation in sea
5. IN LAW ENFORCEMENT
Can detect hiders beyond smoke and fog
THERMAL VISIBLE(FOG)
25. ADVANTAGES
1. Fast inspection rate
2. Non-contact method
3. No harmful radiation produced
4. Easy to interpret
5. Wide area of application
6. Cheap rate
7. A large surface area can be scanned in no time
8. Presented in visual & digital form
9. Software back-up for image processing and analysis
26. DISADVANTAGES
1. In active IRT often non-uniform heating
occurs
2. Thermal losses of specimen
3. Mostly surface defects only detects
4. Unable to detect the inside temperature if
the medium is separated by glass/polythene
material
27. CONCLUSION
By infrared thermography ,can detect the heat
signatures of anything that emits the heat
In construction industry it is useful to detect the
surface defects and to a certain thickness of
concrete ,the heat signatures can be monitored
So the diagnosis of building and other structures
can be conducted
It has many advantages and wide application in
many fields so the use of IR camera is largerly
used