What is Infrared Radiation?
We have all seen how sunlight passing through a prism is broken into the colors of the visible light spectrum. Each of these "bands" of color has a different wavelength. Experiments in the early 1800's using a simple prism and thermometer showed there were "bands" of the electromagnetic spectrum beyond those visible to the human eye. They were called "beyond red" or infrared.
How is Infrared Radiation Measured Today?
All objects on earth emit this invisible thermal radiation or "heat energy". Infrared cameras detect and record the thermal radiation emitted by objects and convert the radiation data to visible images called thermograms. Temperatures of objects in the image can also be displayed.
Infrared Thermography : Practical Uses
Infrared Thermography is used to diagnose the condition of building components such as roofs, walls, insulation, and energy losses through air leakage. Moisture damage caused by leaks in the building envelope or by condensation can be located by non-destructive thermal inspections before building materials become severely degraded. Aerial coverage is available for large buildings and roofs. Thermal imaging is also a useful tool for electrical inspections to locate points of high resistance or overloads before equipment failure. Infrared thermography is invaluable in mechanical inspections for excessive friction or overheating of electrical motors or hydraulic systems. Concrete Masonry Units (CMU) or "block walls" can be quickly inspected for proper placement of grout and rebar, allowing for quality control monitoring during the early phases of construction.
Flat commercial and industrial roofs are expensive to replace, and, unfortunately, they nearly all leak at some time. Roof moisture inspections using infrared thermography can help avoid costly repairs and replacements by identifying areas with wet insulation. Because of the difference in the thermal signature of wet versus dry insulation, suspect areas are marked for repair before extensive structural damage occurs. New roofs should be inspected after construction to provide a baseline roof report and to ensure there are no leaks while the roof is under warranty. Trending can be accomplished by re-scanning the roof every 2 to 5 years for comparison with the baseline report. Thermal surveys are also recommended before purchasing a commercial building or before re-roofing over an existing roof. Preventive maintenance that includes thermal imaging can more than double the life of your roof!
Most problems in electrical systems are caused by abnormal heating due to high resistance or excessive current flow. Infrared thermography is used to quickly locate "hot spots" so repairs can be made before catastrophic failures. Poor connections, current overload, and phase imbalance problems can be identified safely using non-contact thermal imaging. Electrical switchgear, motor control centers (MCC), data centers, transformers, fuses, circuit breakers, and panel boards can all be inspected using infrared thermography. We also provide and install quality Iriss ® infrared inspection windows, making electical inspections safer, faster, and more accurate.
Motors can have hundreds of electrical connections that can become loose or faulty. Motors are rated by class for their maximum operating temperature. Temperatures in excess of these maximum ratings will cause damage to insulation on the windings, greatly shorting the life of the motor. Thermal imaging can detect problems before costly failures, thereby reducing down time. Thermal inspections of pumping systems also include an energy efficiency assessment using the Pumping System Assessment Tool (PSAT) provided by the U.S. Department of Energy. This software tool identifies energy savings opportunities in pumping systems and quantifies those opportunities in both dollars and electrical energy savings. Inspection of Mechanical Systems:
Industrial plants contain a wide variety of equipment with moving parts. Excessive friction found in gears and bearings, defective heat exchangers, blocked or inadequate fluid flow, and abnormal electrical resistance are a few of the problems that can be documented with thermal inspections. Images generated during a thermal inspection provide temperature data that allows for repairs to be prioritized, depending on how critical a failure may be. Refractory insulation, pipe insulation, tank levels, steam traps, and hydraulic systems can all be inspected using infrared thermography. Inspections are safe because thermal imaging is non-contact and non-destructive. Because inspections must be conducted when equipment is in use and under load, there is no costly down time for the facility.
One non-traditional use of infrared thermography is to determine if concrete reinforcing (grout and rebar) has been properly placed in Concrete Masonry Walls (CMU) or "block walls". CMU walls are commonly used to build schools, grocery stores, and shopping malls. To that grout and rebar have been installed, traditional methods require that ports or holes be cut into the block wall. They are often installed at every lift height and at all grouted pilaster locations. This method is time consuming, costly, and often requires a dedicated inspector on the job site. Using infrared thermography, CMU walls can be quickly and economically inspected. The grouted cells have a distinctly different thermal signature than ungrouted cells. Results of a thermal inspection provide hard evidence that a building was built to specifications, protecting the architect, structural engineer, general contractor, and owner from liability.Thermal surveys are conducted by qualified Level I or Level II Thermographers based on nationally recognized standards of the American Society for Nondestructive Testing (ASNT). All surveys are fully documented with a hard copy report containing images of problem areas on CD-ROM in a PDF PowerPoint presentation format. Call to discuss how infrared thermography applies to your Preventive Maintenance Plan.