Small lighting knowledge | flux is what? - China lighting network

We know that the different wavelengths of the electromagnetic wave radiation light source into the surrounding space, Light waves) , the propagation of light propagation process is energy. In unit time by the radiant energy of the area, is called by the radiation flux of the area, how much it reflects objectively the light source of radiant energy. For the 'W' ( Watts) For the unit to represent the radiation power from it? ( The radiation flux) 。 This radiation flux, contains various wavelengths of electromagnetic waves, such as infrared, ultraviolet, visible light, etc. For visible light, the sensitivity of the human eye to different wavelengths of visible light is different, the different wavelength, but the same light radiation flux, the brightness of the damage to the human eye is not the same feeling. Such as the yellow green light, red and purple light let a person feel much darker. The characteristics of the human eye is called the spectral luminous efficiency ( Vλ) 。 Due to the characteristics of the human eye, we can't directly with light radiation flux to represent the size of the visible light energy, and must be in the light of the human feeling, the light of the radiation flux has visual effect 'strength', 'how much' to indicate the amount of light source, with luminous flux in photometry said. The unit of luminous flux called lumen (' lm) 。 The 16th international conference on measurement resolution, 1979, 1 watt power, wavelength of 555 nm of monochromatic radiation flux is 683 lm. YanZhiXiang

just love reading