摘要 |
PROBLEM TO BE SOLVED: To provide a metal halide lamp in which the illumination of ultraviolet light near a wavelength 365 nm is more than a certain level, and the illuminance maintenance rate is high as the lighting time elapses. ! SOLUTION: A metal halide lamp emits ultraviolet light, the metal halide lamp having a light-emitting length in a range of 1000-2500 mm. In order to emit a strong spectrum especially in a wavelength 350-380 nm of ultraviolet light, a luminous tube is filled with a rare gas and at least mercury and iron. The iron is contained as an iron halide composed of an iron bromide FeBr2 and an iron iodide FeI2, the total iron halide FeX2 is in a range of 1.0×10-7≤FeX2≤10.0×10-7 (mol/cm3), and the ratio of iron bromide and iron iodide composing an iron halide is in a range of 3≤FeBr2/FeX2≤10 (molar ratio %), when representing by the iron bromide/iron iodide FeBr2/FeX2. ! COPYRIGHT: (C)2014,JPO&INPIT |