Thermographic Testing

Vibrotech

Reliability

Services

Limited

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

• Switch Gear

• Fuse boxes

• Cable runs

• Electrical connectors

• Insulation

• Transformers

Junction Box

22.7°C

43.7°C

25

30

35

40

SP01

Fan

18.7°C

37.4°C

20

25

30

35

AR01

Fuse Box

23.3°C

38.1°C

25

30

35

LI01

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

Refractory Linings

• Torpedo ladles

• Boilers

• Furnaces

• Exhausts

• Ducting

• Kilns

Rotary Kiln - Access Door

77.8°C

129.3°C

80

90

100

110

120SP01

SP02

SP03

SP04

LI01

Kiln - Refractory Lining

22.5°C

48.7°C

25

30

35

40

45

SP01

SP02

SP03

22.6°C

58.5°C

30

40

50

SP01

SP02

SP03

LI01SP04

Torpedo Ladle

Steel Carrying Ladle

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

Refinery & Petro-Chem

• Vessel Surveys

• Blockages

• Defective lagging or insulation

• Steam traps

• Erosion / Corrosion

Vessel Surveys

Flare Stacks

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