Long-term stability of LED filament standard lamps for total luminous flux

Abstract

NIM has developed LED filament standard lamps for total luminous flux with excellent long-term stability, uniform distribution of luminous intensity, and the E27 Edison screw base which is compatible with present incandescent standard lamps. The standard lamp consists of six high-power LED filaments which are sealed in a G150 glass bulb and filled with He gas. All the 12 lamps were aged for 500 hours before the 315 days’ long-term stability test. 9 lamps are lighted for 1 hour every day. One lamp is continuously operated for about 6000 hours, and 2 lamps are well stored on a shelf. The results show that the long-term stabilities of the 3 cases are better than 0.07%. This LED filament lamp could be promising as a transfer standard of total luminous flux.