Cool Tools: Thermal Imagers
Published: November 2012
Thermal imagers are playing an increasingly important role as a diagnostic tool for immediately identifying potential problems by quickly scanning electrical system connections, fuses, junction boxes, switchgear and other components.
Rapid improvements in infrared (IR) thermal imaging products make it easier for users to take advantage of the potential that thermal imaging offers and help spur usage of IR imaging technologies.
Flir Systems and Fluke Corp. have developed broad lines of thermal imagers, and well-known names in the market also offer such products, including Ideal Industries, Greenlee and Milwaukee Electric Tool Corp.
“Among electrical contractors, a fresh new way of thinking about thermal imaging is emerging, enabled by advancements in the market,” said André Rebelo, Flir Systems’ communications manager. “A number of leading-edge technologies are being integrated into infrared troubleshooting to accelerate and improve the efficiency of diagnostic/repair/approval workflows and processes into what is a true ‘diagnostic ecosystem.’”
Michael Stuart, Fluke thermography marketing specialist and level III thermographer, said electrical contractors with service provider models have begun using thermal images as a “leave-behind” for clients.
“Because thermal images communicate so vividly,” Stuart said, “contractors can use them to convey the value they bring, both on the spot during site visits and in regular reports and upgrade or repair recommendations. A thermal image shows the client something about his facility he can’t otherwise see, and the contractor’s accompanying analysis of the problem substantiates his value-added skills.”
Stuart said the most common application for thermal imagers across all electrical market segments is inspecting electrical and electromechanical equipment and components.
“Differences in temperature—either between phases, between components or between periods of time—indicate a change in operation potentially beyond the thresholds that equipment is designed for. Harmonics, imbalance and simple looseness/tightness can all be identified in electrical panels via their heat signature, and early detection avoids tripping and component failure,” he said.
In electromechanical equipment, he said, overheating indicates mechanical wear or unbalance in time for an isolated component to be repaired, before the entire unit fails. Other industrial--electrical applications include inspecting steam lines and tanks and a range of equipment from kilns to conveyors.
For residential work, thermal imagers are not used as much for service troubleshooting. Applications tend more toward retrofits: locating live electrical behind walls, inspections before bidding on jobs and, in some cases, inspecting finished work, Stuart said.
Fluke offers multiple thermal im-agers, ranging from entry-level to high--performance models, and software for analysis and reporting.
Flir’s Rebelo said products available today represent a quantum leap into the future for the ways electrical contractors think about thermal imagers.
“We’re no longer talking about a thermal imager as an individual tool,” he continued. “Think of a diagnostic ecosystem as a sort of social network for electrical contractors. Workers, equipped with better tools to collect, analyze and document findings, can communicate higher quality information more efficiently and in real time to customers, or in plants, to managers or decision-makers. The result is approval for repairs more quickly and with better documentation. With less isolation and more collaboration, this new way of working helps accelerate critical tasks while reducing cost and hazard exposures.”
The newest thermal imager models provide better accuracy, higher resolution and higher thermal sensitivity offering users detailed thermal images where problems really jump out, he said. High-performance infrared cameras with new imaging capabilities help users find and capture evidence of problems more easily and with dramatically more vivid thermal images.
“In addition to sharp thermal resolution,” Rebelo said, “multispectral dynamic imaging adds the detail of real-time visible spectrum images captured by the built-in digital camera to thermal spectrum images, providing extraordinary sharpness, contrast and clarity never seen before in infrared. Going beyond image blending or thermal fusion, the result is a crisp, full-screen IR image that dramatically reveals problems while adding context to images. For example, informative labels on electrical equipment and nearby signage no longer disappear in thermal images. Problem areas are instantly highlighted for easier orientation to see what needs repairing.”
In terms of ease of use, Rebelo said significant advances include touchscreens, intuitive menus, remote control using smartphones or tablets, and the ability to create reports on the camera’s display.
Thermal imagers can be used anywhere temperature might indicate an anomaly.
“For example, in a hospital, corroded electrical connections concealed in an overhead busbar duct that are heating up can be identified. In a plant, an under-lubricated and overheating motor is caught before a failure would require a costly and unexpected replacement instead of a planned repair. Medium-voltage cubicle panels control and protect electrical machines and lines. With an infrared window installed on the panel doors, an electrical worker uses an infrared camera to inspect energized internal electrical components for temperature abnormalities without the direct exposure from removing covers and panels,” Rebelo said.
For residential work, many of the same scenarios apply on a smaller scale; for example, the inspection of electrical panels where overloaded or deteriorated circuit-breakers glow brightly on the screen of a thermal imager.
Flir’s thermal imager line includes entry-level point-and-shoot models, mid-level professional and performance-grade with higher resolution, accuracy and sensitivity and high-performance-grade for maximum diagnostic capabilities.
Proper training is essential to get the maximum benefits from thermal imaging technology.
At Flir’s Infrared Training Center, electrical contractors can participate in a variety of thermography courses. Classes are available at the ITC in Nashua, N.H.; at locations around the country, including job sites; and online through virtual classes.
Fluke offers in-the-box videos, online webinars and in-person seminars, and it partners with the Snell Group to provide certification training in thermography.
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at firstname.lastname@example.org.