Thermal imagers were developed in the 1960’s and used extensively by the military. Use of thermal imagers in the fire service began in 1984, but it wasn’t until 1997 when ISI introduced the VISION line of thermal imaging cameras that their use became widespread.

With the introduction of the VISION 3 in 1998, ISI produced the first thermal imaging camera to utilize the Raytheon BST thermal sensor. The Raytheon Digital BST sensor is used in the ISI Surveyor and Digital Navigator thermal imagers. And now, the ISI2500 uses the Raytheon Amorphous Silicon Core, allowing for a smaller, less expensive thermal imager.

ISI’s thermal imagers are very helpful when firefighters are trying to find the source of a fire. Thermal imaging is the process by which thermal radiation is transformed by use of an infrared detector into a video image. All objects emit thermal radiation. Special optics inside the camera collect thermal radiation and focus it onto the infrared detector. The detector then transforms this radiation into electronic signals that can then be used to display a video image of a scene.

Today’s thermal imagers have gone far beyond the “see through smoke” application. Thermal imagers provide firefighters with valuable, time saving information for rapid scene analysis including hidden fires, structural degradation, hazardous environmental conditions and spot temperatures. Thermal imagers do not save lives, firefighters do. However, thanks to thermal imagers, firefighters now have a tool that allows them to do their job more safely and in a fraction of the time.