Lamps and light attenuation, refers to lamps in over a period of time after the lights, lower intensity than the light intensity, and the lower part is the light of lamps. Different types of lighting, of light attenuation caused by different reasons.
For ordinary incandescent lamps, lamp bulb larger lumen is smaller, and evaporation deposition of tungsten shielding the light output is proportional to. Gas-filled bulb as some of the gas to prevent evaporation of tungsten wire, so light attenuation will be relatively small.
If the same filament for incandescent lamps, different size bubble shell, relatively light bulb at the same time smaller than a small bulb. In addition, the same air bubbles, glass bulb inside a large space, gas convection glass large radiating area, relatively small glass bulb lamp temperature much lower filament temperatures are relatively low, low luminous efficiency, rate of evaporation of the tungsten filament is also low, so light is smaller.
Incandescent lamps because of the size and due to evaporation of the tungsten filament light bulb, fluorescent light attenuation due to the relatively complex, typically caused by the following reasons:
Deterioration of Phosphors, fluorescent light working process, the UV light makes the phosphor to produce color centers, cause the lamp to produce the new absorption bands, so that the brightness of the Phosphor decay occurs.
Optical thin film formation, after long time working in fluorescent light, phosphor surface forming a layer of black light-absorbing film, this absorbing film causes the reduction in light output.
Black lamp, fluorescent light working when the glass surface will have a lot of mercury or mercury atoms, mercury and other ions by ion exchange in glass tubes, the years, are blackening of the glass tube, resulting in a fluorescent light failure occurred, affecting efficiency.
LED lighting failure
LED lights than incandescent and fluorescent lighting has improved, but cannot overcome light failure problem. LED light mainly in the following two factors:
LED product quality problems
LED chip quality, brightness decay more quickly.
Production defects, LED chip cooling export not good from a PIN the feet, lead to increased temperature is too high the chip LED attenuation.
LED constant current driver, some LED lamps with voltage-driven reasons, LED decay too quickly.
Drive current is greater than the rated driving conditions.
Led LED light failure for many reasons, but the most important is heat dissipation. Better heat dissipation, LED working temperature, the lower the lumen is smaller, the LED life is longer.
Light attenuation is a necessary process of lamps, while our selection of lamps, should be selected for quality and good heat dissipation of lighting, in the process should also be used to minimize the workload of the lamps, to delay the speed of light, extend lamp life.