Frequently Asked Questions
Information that be be useful for a better understanding of infrared thermography and other applications.
Infrared General
Q: What is infrared thermography?
A: A technique for detecting variations in radiated energy and
transforming them into visible images that can be recorded and
interpreted.
Q: What does "Certified Infrared
Thermographer" mean?
A: Certification of thermographers is handled in several ways. Some
employers certify their on site thermographers and others are
certified by an outside source. There is no single criteria
for certification. Consideration should be given to the source of
the certification. IBD certifications are issued by Infraspection
Institute.
Q: What is emissivity?
A: A simple definition is a measure of how well a surface emits
radiation. A surface with a high emissivity will emit more radiation
and be easier to view with an infrared camera. A surface with
a low emissivity will reflect more "background" radiation and will
be more difficult to view.
Q: What can be inspected with an
infrared imager or camera?
A: There are many applications for using an infrared camera to
locate problems that are unseen or difficult to locate visually.
New applications are realized each year. Problems that relate
to moisture, building structures, energy loss or movement,
electrical and mechanical are some of the more common applications.
There area also applications in veterinary, medical and other
fields. It is best in all applications to consult with a
qualified thermographer to determine if infrared is suitable.
Commercial Building
Q: What are some applications for
infrared in commercial buildings?
A: Depending on the location, some common uses include energy loss
surveys, locating hidden moisture and locating structural members.
Q: How does infrared locate moisture?
A: Moisture in building materials can change the thermal properties
including the materials ability to retain or release heat. An
infrared camera can detect small differences in energy emitted or
radiated from the surface of most materials. Areas of a roof
or insulated wall assembly that contain moisture will often show a
pattern that is different from a dry condition allowing these areas
to be located.
Commercial Roofing
Q: Can my roof be inspected using
infrared thermography?
A: Most roofs can be inspected. Some roof systems such as a
ballasted single-ply require conditions that may only happen a few
days each year or not at all. These systems can be inspected
for moisture using a nuclear moisture gauge. Some smooth roofs
are difficult to inspect with some cameras. It is best in all
applications to consult with a qualified thermographer.
Electrical and Rotating Equipment
Q: Can we use a point radiometer to
inspect our electrical system?
A: Point radiometers measure the temperature of an area that is
dependant on the distance from the target. The area may be
smaller or larger than the intended target and often the measured
temperature will not be accurate, especially for smaller hot spots.
Unlike infrared cameras, there is no image to view or record.
Q: How often should we have an infrared
inspection of our electrical system?
A: "NFPA 70B: Recommended Practice for Electrical Equipment
Maintenance" states that infrared inspections of electrical systems
should be performed annually or more frequently if warranted.
Q: What is NFPA 70E?
A: NFPA 70E is the "Standard for Electrical Safety in the Workplace"
published by The National Fire Protection Association. The
standard defines guidelines for working on and around energized
electrical equipment. Thermographers should be familiar with this
standard.
Residential Applications
Q: Can infrared thermography be used on
a residence?
A: Yes. Hidden moisture, energy loss and structural details
can be located using thermography.
Nuclear Moisture Inspections
Q: What is a nuclear moisture inspection or survey?
A: A nuclear moisture gauge uses non-destructive testing technology
of neutron thermalization and is used on a low-slope commercial roofing
to determine the extent of moisture intrusion into the roof system. They can be used on most types of roofs,
but are more common on ballasted single-ply systems, which are
difficult to inspect using infrared.