Infrared imagery is often a grayscale picture whose scales (or shades of gray) represent the differences in temperature and emissivity of objects in the image. As a general rule, objects in the image that are lighter in color are warmer and darker objects are cooler. No object in the images is detected via visible light wavelengths (400-700 nanometers) rather, only from infrared wavelengths in the 3000-5000 nanometers or in the 3-5 micrometers (microns) range. Lights and other relatively hot objects are very evident, but as a result of their heat, and not light emissions. When an image is taken by our infrared camera, it is often recorded on videotape and/or digitally saved to a hard drive and later converted to a digital image file with the help of a computer. The image may then be modified in a number of ways to enhance its value to the end user. The highest resolution infrared images are usually found on the digital media, while the printed pictures may be used as a convenient reference when making the building drawings or accompanying a roof report. Areas of roof moisture contamination often manifest themselves as warmer (lighter colored) areas that may be nebulous in shape and sometimes mottled in appearance, although they are commonly found in linear or puddle-like shapes. The linear shapes many times follow low areas, drainage routes, roof edges and seams. Puddle-like round or oblong shapes often form around roof penetrations such as mechanical equipment, standpipes, vents and drains. The wet areas are lighter in color because the latent heat (from daylight sunshine) in the trapped water mass is greater than in the dry, functioning insulation or roof substrate. After sunset when the roof structure cools down, wet areas of roof insulation and other materials continue to radiate heat, allowing our sensitive infrared cameras to detect the sources of heat and record them for later analysis.

High-angle and straight down (NADIR) infrared and visual images reduce reflections and capture large areas at once, making the imagery easier to analyze and the report less expensive to produce.

Fixed-wing aerial operations are a more cost-effective platform to obtain imagery than rotor-wing, while reducing ferry times and vibrations.

Since images are captured straight-down or ‘plan view’, the report is clear, concise and easy to understand because infrared images, visual images and AutoCAD® drawings are reconciled.

Plan view imaging allows for accurate marking of areas of suspect roof moisture contamination. CAD drawings are made by drawing ‘over’ the captured visual and infrared image on the screen. The infrared, visual and AutoCAD® components can then be separated. If dimensional information is available, this creates a quantitative, scaled AutoCAD® drawing of the suspect roof moisture contamination on the roof. If dimensional information is not available, the drawings become scalable and easily updated at any time in the future once quantitative data is obtained.

Access to multiple levels of the roof is never a problem.

The printed AutoCAD® drawings can be used on the roof to paint areas of moisture contamination directly on the roof, if desired.

The aerial infrared thermographer can wait for a good night for imaging, surveying many roofs under good conditions.

To read more about aerial infrared steam system surveys, please visit the Roof Moisture FindIR™ portion of The Stockton Infrared Services web site at: http://www.aitscan.com/roofmoisturefindir.php