Fireye 45UV5-1103 Scanner UV self-checking, 1 inch NPT mount, 50 Hz. Use with 25SU3 and 25SU5. Fireye Type 45UV5 scanners are self-checking, flame sensing devices. When powered by a compatible, self-checking Fireye control, the scanners detect the presence or absence of flames which 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