The problem faced by most property owners is that moisture behind walls, over ceilings, and under floors is often impossible to detect until the problem is excessive and visible to the naked eye. Since the investigation and removal of infestations of not yet visible mold in structures is often difficult, technology is now being used to do what once was impossible.
According to the US Environmental Protection Agency, there is no practical way to eliminate mold spores in an indoor environment. The best way to control mold growth is to control moisture. Mold can begin growth in as little as 24 hours. Roof leaks and water pipe leaks are common sources of water accumulation that may cause mold growth. 1
Technology has provided a tool that can be used by investigators, remediators, and consultants to detect and help eliminate mold infestations. The technological tool is called Infrared Thermography (IT). IT is a technique that produces an image of invisible (to the human eye) infrared light emitted by objects due to the heat, or lack thereof, in the object called its "thermal condition." The most typical type of thermography camera resembles a typical camcorder and produces a live television picture of heat radiation. More sophisticated cameras can actually measure the temperatures of any object or surface in the image and produce false color images that make interpretation of thermal patterns easier. An image produced by an infrared camera is called a thermogram or sometimes a thermograph. 2
To understand IT as a tool it is necessary to understand how it works. Thermal or infrared energy is light that is not visible to humans because its wavelength is too long to be detected by the human eye. Thermal or infrared energy (IR) is the part of the electromagnetic spectrum that we perceive as heat. Unlike visible light, in the infrared world, everything with a temperature above absolute zero emits heat. Even very cold objects, like ice cubes, emit infrared. The higher the object's temperature, the greater the IR radiation emitted. Infrared allows people to see what their eyes normally cannot see.
IT cameras produce images of invisible infrared or "heat" radiation. The IT camera can provide precise noncontact temperature measurement capabilities. The existence of moisture—a substance cooler than normal construction materials—can be used to detect conditions that promote mold growth. Mold related problems can be detected before the mold is visible to the eye or detectable by the nose. IT cameras are extremely cost-effective, valuable diagnostic tools in construction related problems of water intrusion and mold growth.
An infrared camera is a noncontact device that detects infrared energy (heat) and converts it into an electronic signal, which is then processed to produce a thermal image on a video monitor and perform temperature calculations. Heat sensed by an infrared camera can be very precisely quantified, or measured, allowing you to not only monitor thermal performance but also identify and evaluate the relative severity of heat-related problems.
Recent innovations, particularly detector technology, the incorporation of built-in visual imaging, automatic functionality, and infrared software development, deliver more cost-effective thermal analysis solutions than ever before.
But finding a problem with an infrared camera is not a solution. It is the start of an investigation that will help the property owner or developer stop a problem before it becomes serious. An infrared camera image alone, without accurate temperature measurements, says very little about the condition of a structure or its susceptibility to mold growth. An infrared image without measurement can be misleading because it may visually suggest a problem that does not exist.
Infrared cameras that incorporate temperature measurement allow professionals to make well-informed judgments about the operating condition of a structure. Temperature measurements can be compared with historical operating temperatures, or with infrared readings of similar structures at the same time, to determine if a significant temperature rise will compromise the structural integrity or encourage mold growth.
Digital image storage, available on most FLIR 3 Systems infrared cameras, produces calibrated thermal images that contain over 78,000 independent temperature measurements that can be measured at any time with FLIR Systems infrared software products on standard PC platforms.
Used properly, a thermal imaging camera can provide valuable information during moisture assessments, remediation oversight, energy audits, roof and electrical system inspections and water damage investigations. Temperature difference caused by evaporation, radiation, thermal bridging, infiltration/exfiltration, and other sources must all be carefully evaluated. A thermal image, like the image of a roof below, looks like an impressionist painting by an artist on psychedelic drugs.
The inspector trained to properly use the IR camera can read the information to spot suspect areas that are not visible to the naked eye. The findings can later be verified using electronic, data-logging moisture detection equipment and in some cases core samples from the roofs or walls.
The inspector uses thermal imaging and data logging moisture detection equipment to establish that the inspector assesses all areas of concern. The extra verification gives additional assurance that the findings from the IR camera are defensible. All property owners and their insurers faced with a claim alleging mold infestation can find these tools essential to the decision process and proper maintenance of the structure.
When suspect areas are found they can be visually documented using the IR camera. Images, like those obtained from an IR Camera, are easier for a layperson or nontechnical person to understand. Findings from the IR camera can be explained to the property owner or the insurer's personnel combined with the verification obtained by using data-logging moisture detection equipment with time stamp and/or destructive testing.
The time saved using infrared, and the larger areas covered rapidly by an IR Camera, can save time and money by providing a faster, more efficient and more reliable survey. An IR camera can detect moisture located behind interior walls under the right conditions. The temperature difference created by the presence of moisture on the inside surface of a wall will appear differently than the surrounding area. IR and IT experts recommend that property owners or their insurers should use IR cameras and IT for moisture detection under the following circumstances.
Infrared technology is especially useful for inspecting flat roofing systems and synthetic stucco systems, which rarely give any visual clues as to their condition or the location of leaks and moisture retention. Litigation involving synthetic stucco, or exterior insulating finish systems (EIFS), is rampant nationwide. EIFS exterior cladding is blamed by many property owners for retaining moisture behind. The property owners claim that EIFS, because it retains water behind it, promotes mold growth and rotting within exterior wall cavities.
IR technology is being supplemented with a living tool: dogs trained to sniff out the existence of mold. For example, Lab Results LLC, 4 brought the first certified Mold Dog™, Oreo, to the Northeast and provides a network of independent certified mold dog handlers ready to take on big jobs when needed. While a mold-detection canine can quickly find mold inside a home or commercial building, infrared thermal imaging has the edge on the exterior and in detailing—with imagery, the location, and extent of mold infestation.
Properly used under the right conditions, infrared thermography can serve as an early warning system for flat roofs that tend to retain water long before they actively leak. The technology also can detect temperature variations that an infrared thermographer would use to find moisture accumulation, condensation, infiltration, and leakage in wall systems and windows, all of which can provide an environment conducive to mold growth.
The combined use of Mold Dogs™ and infrared thermal imaging during EIFS inspections can be one of the most effective nondestructive and non-invasive method of surveying a property for potential mold and moisture problems. The combination can tell a property owner or potential buyer whether there may be a serious hidden problem, before any cutting or sampling is done.
Typical current inspection methods involve much guesswork and the random cutting of core samples or pieces of walls—both inside and out—to analyze for mold and moisture. A combined Mold Dog™ and infrared thermal imaging inspection can protect a potential buyer from acquiring a lemon property or from incurring repair and remediation costs far beyond a building's value.
A mold problem is a moisture problem, so when IR is used to find moisture, and it actually finds moisture, it becomes possible to prevent mold and rot from taking hold or to remove the mold that actually grows. Some examples of IR Cameras that can be used for IT inspections of structures to avoid mold growth follow. (The descriptions and photos were taken from the manufacturer's website and are not intended to be an advertisement for or endorsement of any of the products.
Palm IR 500.The latest and greatest thermal imaging camera from Raytheon. The new Palm IR 500 is the first radiometric camera from the company based on their exclusive BST detector technology. Early reports indicate that the image is much improved and temperature measurement should be accurate within range. The system looks like a winner and the Compaq IPAQ is a nice bonus. This is a fantastic imager for every application including predictive maintenance, energy audits, printed circuit board scans, and more.
Palm IR PRO Specials.Packages for the latest in thermal imaging performance. The IR PRO combines high resolution imaging, comfortable LCD viewing, and Digital Compact Flash image storage. We have special packages for Predictive Maintenance, Home Energy Audits, and Security/Surveillance applications.
Palm IR 250 DIGITAL.The venerable IR 250 has been much improved with its latest overhaul. "We have a completely new product here and it kicks butt!" The New digital detector produces a super crisp image and the variable digital zoom you have all been waiting for is finally here. Convenience features like numeric on-screen gain and level symbology and our newest value added packages make the IR-250 D an interesting proposition.
Palm IR 225.The newest addition to the NightSight family is the IR-225 compact thermal imager. This new unit shatters the $10k barrier to bring you quality Raytheon imaging at the greatest possible value. This is one unit that you can truly afford to implement on a widespread basis.
Similarly, FLIR ThermaCAM® E4 infrared camera features image post-processing, plus alarming and multiple target spots in rugged 1.5 pound package. The Model E4 introduced the use of a radiometric JPEG (Joint Photographic Experts Group) image format that allows image post-processing on the camera or on a PC. As a result, the E4 also provides three independent, movable spot temperature cursors, and audible "beep" alarming for high, low, or temperature-difference thresholds.
The radiometric JPEG file format integrates thermographic functionality with the familiar, world-standard JPEG file format used in Web and other graphics environments. The E4 can store images as radiometric JPEG files, which retain full thermographic functionality. It can also store images as nonradiometric JPEG files. Both radiometric and nonradiometric JPEG formats can be readily inserted into standard word processing and desktop publishing applications. 5
An IR camera can look at a wall after a fire and show where water has accumulated that would be invisible to the human eye. A modern advanced IR camera is literally a handheld personal computer that measures temperature with an advanced focal plane array detector. The most powerful cameras provide 12-bit recording, enabling users to view and measure a scene that contains very hot and very cold temperatures without losing the ability to measure thermal variations of less than 0.1 deg C.
Camera options, such as bar code readers for image tracking, have extended the functionality of IR imaging systems to match the needs of computerized maintenance management systems (CMMS). Bar code tracking offers accurate, operator-independent data entry that adds pertinent condition comments directly to the stored IR image. Even where bar codes are not used to identify equipment, the bar code standardizes all inspection comments associated with the image.
At the completion of an inspection task, stored images are usually transferred to either a stand-alone thermal analysis or reporting software package, or to the main CMMS. Regardless of the type of maintenance management system at a facility, the primary task at this point is to archive collected data and generate work orders for corrective actions. When required, a full range of image analysis software features allow the user to extract temperature values from the stored images on any PC with the Windows operating system.
IR system suppliers are delivering real-time IR workstations that can measure dynamic temperature changes in equipment and processes. The call for more sophisticated application of IR imaging is often initiated after production and engineering departments have battled quality or efficiency problems in the construction of structures that encourage mold growth. The problems may range from poor adhesion of hot-set glues to quality variations in plastic films, from poor uniformity in glass products to roofing materials that are not water-tight; from windows that leak to water wicking up through concrete slabs.
It is not uncommon that as management pushes for increased quality that effective methods of testing quality and avoidance of water intrusion are needed by everyone in the business of owning or building structures. In these production situations, the new real-time IR thermal imaging systems are most useful. The systems consist of two primary components:
A key feature is the digital video interface, which transmits every temperature measurement pixel generated by the camera. The camera also can be disconnected from the system and used in traditional snapshot mode. What makes these workstations so useful for troubleshooting construction problems is their ability to acquire, store, and analyze sequences of real-time IR images of the structure under investigation or during construction. The system analyzes, displays, and stores up to 60 calibrated IR images every second. The systems use off-the-shelf components to make upgrades possible and ensure compatibility with traditional software.
A relatively slow and inexpensive 200 MHz Pentium PC with its high-speed PCI bus makes an excellent platform for thermal imaging. A digital frame grabber accepts the digital video transmitted by the camera and transfers it to the high-bandwidth PCI bus. High-capacity hard disk subsystems designed for multimedia applications store the data for subsequent review and further analysis.
Software analysis tools give the system a VCR-like user interface for controlling the digital video recording and playback. Users first position the camera and adjust the viewing temperature range and then select the rate and length for which images are stored to the internal drive, ranging from 60 Hz for as long as 20 minutes, or as slow as one image every hour for weeks. Storage of the video can be initiated from the keyboard or a signal from the device under observation. Once data have been recorded, viewing controls (such as play, fast forward, rewind, slow motion, and time lapse) can be used to review the process, equipment, or event under study.
The software provides a full range of tools for extracting temperature data from the collected thermal image sequence. They range from simple points, areas, and lines to complex regions that help the user measure only specific components of interest. If live sequences reveal dynamic trends, a tool automatically extracts data from a sequence of images and generates a graph for review. Captured data can be exported to other systems so maintenance managers can integrate all maintenance test data into a CMMS. 6
FLIR Systems, Inc., suggests the following when considering the purchase of an infrared camera.
Most infrared cameras have fewer pixels than visible-light cameras. It is best to consider carefully detector resolution. Higher resolution infrared cameras can measure smaller targets from farther away and create sharper thermal images, both of which add up to more precise and reliable measurements.
Also, be aware of the difference between detector and display resolution. Some manufacturers will boast about a high resolution LCD and hide their low-resolution detector when it's the detector resolution that matters most. Higher resolution thermal imaging not only provides more accurate quantitative results, it can be very effective in showing findings in finer detail. Superior IR image quality is also valuable for generating clearer reports and for marketing your services.
Many affordable IR cameras now include a built-in digital camera that simultaneously captures visible light and thermal images. Digital photos that correspond to your IR images will help further document a problem and communicate its precise location to decision-makers. Be sure that it includes an onboard lamp that doubles as a flashlight to illuminate darker areas.
Built-in laser pointers are also invaluable, especially for isolating the location of a target surrounded by similar-looking components.
Infrared cameras don't just let you see differences in heat, they let you measure those differences, which means the accuracy and consistency of the measurements is a very important factor when determining the value of a camera. For best results, look for a thermal imager that meets or exceeds +/- 2 percent (or 3.6°F) accuracy.
Some cameras offer a standard JPEG with full temperature analysis embedded. This allows you to email IR images to your customers or colleagues without losing vital information. Radiometric JPEGs can also be imported from Wi-Fi compatible cameras to select mobile devices using apps that provide further image editing, analysis, and sharing. Also, look for infrared cameras that allow you to stream MPEG 4 video via USB to computers and monitors.
New test and measurement tools now allow certain thermal cameras to measure more than temperature to fully quantify the severity of moisture damage and electrical issues. These moisture and clamp meters wirelessly transmit vital diagnostic data such as humidity, amperage, voltage, and resistance directly to the camera.
It's now possible to connect some cameras via Wi-Fi to smartphones and tablets. The advantage of being able to send thermal images and IR inspection reports wirelessly from one part of a facility to another or by email from the field is huge when time is of the essence.
The camera's weight can be a significant concern if you'll be using it frequently or for extended periods of time. Another important thing to consider is the camera's interactive controls. Does it have dedicated buttons, direct-access menus, or both? Make sure your camera is outfitted with at least two batteries (lithium ion or better) that can be quickly and easily switched out in the field so you can keep working efficiently.
Some thermal imagers allow the generation of instant reports right in the camera and/or using an app on mobile devices connected to Wi-Fi enabled cameras. IR analysis software can perform a wide range of tasks from simple spot measurements to custom radiometric calibrations.
A camera's temperature range and sensitivity are important considerations, too. The range tells you what the minimum and maximum temperatures are that the camera can measure (-4°F to 2,192°F is a typical example). Select an IR camera with a temperature range broad enough to capture all of the temperatures of the objects or scenes you typically encounter.
The quality of customer service and the depth of technical support available should be integral to your decision on which infrared camera to purchase.
For more information, visit flir.com.
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