Thermal Imagers – Seeing through the Smoke
There is little doubt that thermal imagers (TIs) save lives. Lifting the veil of thick smoke and restoring sight greatly reduces search time, improving the odds of rapidly locating and extricating trapped victims. The primary benefit for using thermal imaging technology is the improvement to firefighter safety. When firefighter visibility is restored, safety is dramatically increased.
There are a wide variety of thermal imagers available for fire departments today, including handheld thermal imagers that weigh less than a kilogram and incorporate the latest technology in ultra-high resolution detectors, advanced colorization, enhanced image clarity and picture definition. As more and more fire departments look to purchase thermal imagers for their firefighters, manufacturers will continue to push the technology limits of these devices. Let’s look at the technology behind thermal imaging.
Thermal Imaging Technology
All objects have a certain temperature and emit waves of energy called infrared radiation. The hotter an object, the more energy waves are emitted. A thermal imager translates these energy waves into a viewable image that displays a “heat picture” of a scene. On the screen of a thermal imager, hottest objects show as white, coolest objects show as black, and features of other objects show as shades of gray.
Since infrared radiation is not blocked by smoke, firefighters can use thermal imagers to see clearly through smoke, which the human eye cannot. This “thermal picture” enables firefighters to find victims faster, identify the source of the fire earlier, and detect structural dangers that put firefighters at risk. Thermal imagers cannot see through walls, glass or other solid objects, but they can detect heat that has transferred to the surface of an object. The imager’s detector receives electromagnetic energy and converts it into an image. Using this technology, firefighters can see heat signatures as small as footprints or handprints.
Thermal radiation is simply a portion of the electromagnetic spectrum. The electromagnetic spectrum describes radiation in terms of energy. Higher energy creates shorter wavelengths and improves penetration. Lower energy produces much longer wavelengths and improves distance.
What are the benefits of this technology for the fire service?
Improved Firefighter Safety
Firefighters used to search burning buildings on their hands and knees, racing against time to find unconscious victims. Today, with the help of thermal imaging technology, firefighters see through smoke, cutting their search time by more[than half and increasing the chances victims will survive. Originally, thermal imaging technology was designed for use in the military in the 1950s and 1960s to help soldiers navigate during night missions and across smoke-covered battle fields. This thermal imaging technology that worked so well for the military was declassified in 1996 and subsequently applied to other applications, including the fire service market.
Of all the operations in which thermal imaging can improve a firefighter’s efforts, this technology has the most dramatic impact on search and rescue. Firefighters using thermal imagers can see the scene, which enables them to quickly navigate and identify victims. In addition to allowing firefighters to see through smoke in burning structures, thermal imagers enable first responders to see in the dark to find victims or fellow firefighters who are lost or in danger.
Firefighter disorientation is one of the leading causes of firefighter deaths during structural firefighting. Disorientation occurs when firefighters lose their sense of direction when visibility inside a structure is close to zero. Once disoriented, the firefighter has only a limited amount of time to find his/her way out of the structure or call for assistance. Equipping each firefighter with a thermal imager means firefighters now have more “eyes” in a fire, lessening the likelihood that a firefighter will become disoriented, trapped or lost. Having a thermal imager in the hands of every firefighter improves the efficiency of search operations and lessens property damage because firefighters can move faster through a fire scene.
With more “eyes” in a fire, firefighters have more opportunities to spot various hazards and dangers, such as increasing heat levels, structural weaknesses in the floor or ceilings, hanging electrical lines, stairs or skylights, fallen furniture and other household items. In addition, if a thermal imager is dropped or lost, firefighters can rely on the other thermal imagers to navigate the fire. Equipping each firefighter with a thermal imager increases the speed at which a crew can travel through a fire, improves accuracy, and reduces errors in image interpretation. Putting more thermal imagers into the hands of trained and capable firefighters can dramatically improve the efficiency of fighting fires.
Thermal imagers have become much more sophisticated based on the technology improvements and the market’s demand for a higher quality TI experience. Today’s thermal imagers provide high-quality scene interpretation, record video for training purposes, and give directional guidance to a team that is moving through a structure. As fire departments become more and more accustomed to using thermal imagers, the expectations of improved scene interpretation and higher quality imagery are understandable but also expensive.
Fire departments evaluate the need for thermal imaging based on how deeply ingrained thermal imaging has become within their fire department. Typically thermal imaging is evaluated on four levels: one thermal imager for the entire department; one thermal imager per station; one thermal imager per apparatus; and one thermal imager per firefighter. The fire department that uses the latter model is on the cutting edge of thermal imaging technology. A fire department that has adopted this model has moved beyond search and rescue and has begun to address the issues of firefighter disorientation and firefighter safety by equipping each firefighter with a thermal imager. Everyone engaged in fighting the fire now has sight. This is the future of thermal imaging for the fire service.
Thermal imagers are available at a wide array of price points with different features and options available on different units. Like any tool in the firefighter’s arsenal, the expense of purchasing a thermal imager must be balanced against the benefits. Increased firefighter safety and operational efficiency, decreased search times and rekindles all reinforce the value of thermal imaging and why fire departments need this life-saving tool.
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