When powered by a compatible, self-checking Fireye control, the scanners detect the presence or absence of flames that emit ultraviolet radiation (UV). Typical fossil fuels which emit UV include natural gas, propane, methane, butane, kerosene, light petroleum distillates and diesel fuels. For burners firing steam-atomized oil or pulverized coal, Fireye recommends the use of infrared (IR) scanners. Fireye offers a complete line of infrared scanners best suited for these applications.