Frequently Asked Questions
Information that be be useful for a better understanding of infrared thermography and other applications.
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.
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.
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.
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.
Q: Can infrared thermography be used on a residence? A: Yes. Hidden moisture, energy loss and structural details can be located using thermography.
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 insulations of 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.