2. Predictive Maintenance Technologies
Predictive maintenance attempts to detect
the onset of a degradation mechanism with
the goal of correcting that degradation prior
to significant deterioration in the component
or equipment.
The diagnostic capabilities of predictive
maintenance technologies have increased in
recent years with advances made in sensor
technologies.
5. Thermography
Thermal measurement technology
measures temperatures of key
equipment parts or areas being
monitored.
Abnormal temperatures indicate
developing problems.
6. Technology
There are two types of equipment used in
this technology.
Contact methods of temperature
measurement, using thermometers and
thermocouples, are still commonly used for
many applications.
non-contact measurement using infrared
sensors has become an increasingly
desirable alternative to conventional
methods.
7. Advantages of Non-Contact
Thermal Measurement
• Target in motion .
• Target electrically hot . Current-conducting
equipment and components
present a hazard to personnel and
instruments alike.
• Target fragile .
• Target very small .
• Target remote .
• Target temperature changing .
9. Infrared thermography (IRT) –
Infrared thermography is based on
measuring the distribution of radiant
thermal energy (heat) emitted from a
target surface and converting this to a
surface temperature map or thermogram.
Infrared thermography is the technique of
producing an image of invisible infrared
light emitted by objects due to their
thermal condition.
15. Electrical Applications
The primary use for infrared thermography,
and usually the most straightforward
application for it, is in the area of electrical
predictive maintenance. Within this area,
there are three main categories of
problems:
1. high electrical resistance.
2. Hot spots caused by inductive currents
3. open circuits.
16. Electrical - High Electrical Resistance
High electrical resistance is the most common
problem that can be identified by using an
infrared imager. Based on Ohm’s law, power
(watts) is calculated as the square of the
current multiplied by the resistance (P = I2R).
When the resistance is high, the power that is
dissipated will be high.
A higher power translates into a higher
temperature at the same location. This creates
the hot spots that are detected by the infrared
thermal imager.
21. Electronics :Printed circuit board
Typical reasons for
temperature hotspots
or deviations
1. Under designed
components
2. Component failure
3. Improper soldering
4. Broken traces
5. Reversed polarity
22. Mechanical Applications
Friction
1. In the case of rotating or moving equipment, the result
of friction is readily observable as an increase in
temperature. Typical situations evolve in the area of
bearings on pumps and motors.
2. If a bearing or coupling is inadequately lubricated,
internal friction can cause heating, which can usually be
observed during operation.
Valve Leakage /Blockage
1. The leakage of fluid past a normally closed valve might
be easy to observe with an infrared imager.
27. Infrared Applications -Mechanical
Insulation
Insulation on piping and equipment can
be tested for integrity using an infrared
imager.
IR applications include the assurance of
complete coverage of the area,
thinning/degradation of the insulation,
and wet insulation.
28. Commercial Buildings
1. Buildings can be
inspected for energy
conservation with
an infrared imager.
2. Typical problems
that can be found
include HVAC ,air
infiltration or
exfiltration, poor
insulation, and wet
roofs.
Roof inspection
29. Thermal Plume Detection
The use of an infrared imager in a
helicopter or airplane can assist the plant in
verifying thermal discharge patterns in
cooling ponds or other bodies of water. The
thermal plume, or outfall, is easily
observed from the air.
The hottest spots on the surface of the
water are easily located. This facilitates
routine environmental monitoring for
thermal discharge.
30. Correlation of thermal analysis with
other technologies
Technology Correlation
method
indication
vibration Time coincident Increasing or already high
vibration at the same time as
increasing temperature
lubrication Time sequence High and or increasing large
wear particles
Debris
analysis
Time sequence Damage has occurred or is
occurring
Leak
detection
Time coincident Abnormal temperature
coincident with acoustic
signals indicating internal leak
of gas or fluid
Electric
circuit
testing
Time coincident High resistance in energized
circuit radiating abnormal heat
