March 1999

Fire Sight

By Technology Review

Rushing fearlessly into burning buildings, firefighters seem at times like superheroes. If researchers at a company called Zybron have their way, firefighters will actually acquire a superhuman power: the ability to see through a wall of fire that might conceal someone in need of rescue.

Zybron and other firms have already built devices that use infrared detectors to peer through thick smoke. But a fire's bright light and searing heat blots out the weak infrared signal given off by a human body on the other side of the flames. So Zybron, based in Beaver Creek, Ohio, is developing a helmet-mounted system that uses a diode laser to beam out light at a wavelength outside the spectrum of fire. The light bounces off objects behind the fire and back into a detector on the helmet; filters that pass only the laser's wavelength permit the system to create an image of the hidden area, which the firefighter views on a liquid crystal display attached to the visor. Zybron hopes to begin field tests late this year.