What is Thermography?
Infra Red Thermography is a technique for
producing a visible image of invisible (to our eyes)
infra red radiation emitted by objects due to their
thermal conditions
Thermography
Objectives of Test
•To detect hot or cold area’s
•To determine absolute temperature
•To view Thermal profiles
•To detect temperature loss
Thermography
Infra Red is part of the
Electromagnetic
Spectrum
•It travels in straight lines at
the speed of light
•The useful part is divided
between Short and Long
wavelengths
•Use of the correct
wavelength is essential
Test Equipment
•Hand held portable camera
•Battery Powered
•Operating at correct
wavelength
•Range…..-20°c to +1500°c
•Sensitivity…..0.1°c at 30°c
•Real time display
•Image Recording capability
Why Thermography?
•Non Contact
•Rapid Scanning
•Data can be recorded in differing formats
•Images produced are comprehensive &
reliable
•Is there a viable alternative?
Principles of Operation
•Object radiates infra red radiation
•Temperature difference
•Differences are detected and displayed visually
•Emissivity values must be observed
Advantages
•Non Contact
•Non Intrusive
•Can work at a distance
•Fast and Reliable
•Portable
•Convincing Results
Limitations
•Non Intrinsically safe
•There must be a temperature difference for
certain surveys
•Operator experience is essential
•Filters may be needed for certain
applications
•Sensitivity and Resolution reduce with
distance and angle of view
Electrical Connections
Used for the detection of;
•Corroded connections
•Slack / loose connectors
•Connectors at too high an
operating temperature
•Hot spots
Transformers
•Electrical connections
•Insulators
•Thermal profile
•Operating
temperature
•Liquid Level
Building Surveys
Used to detect,
•Lack of insulation
•Cold air infiltration
Draughts
•Moisture traps
•Hot / warm air escaping
•Structural Integrity
•Heating / Cooling
Building Surveys
Building Surveys
Moisture/Water Ingress
•Leaking Roof
•Bridged Cavity
•Leaking pipes
Process Plant
The above Thermograms show how
Thermography can be used as a very fast and
effective maintenance tool.
–The image on the right has a defective cylinder
Process Plant
Thermography may be
used for;
•Corrosion surveys
•Ensuring valve operation
•Leaks
•Blockages
Process Plant
•Hot spots
•Cold spots (Cryogenics)
•Damaged or missing
insulation
•Tank levels
Miscellaneous
•The detection of
process or
manufacturing faults
•Can be used as a
quality control tool