Incandescent lamp is a kind of electric light source which makes conductor hot and luminous after current flows through it. Incandescent lamp is an electric light source made according to the principle of thermal radiation. The simplest kind of incandescent lamp is to pass enough current through the filament to make it incandescent, but the incandescent lamp will have a short life.
The biggest difference between halogen bulbs and incandescent bulbs is that the glass shell of the halogen lamp is filled with some halogen elemental gas (usually iodine or bromine), which works as follows: As the filament heats up, the tungsten atoms are vaporized and move toward the wall of the glass tube. As they approach the wall of the glass tube, the tungsten vapor is cooled to about 800℃ and combines with the halogen atoms to form the tungsten halide (tungsten iodide or tungsten bromide). The tungsten halide continues to move toward the center of the glass tube, returning to the oxidized filament. Because the tungsten halide is a very unstable compound, it is heated and redecomposed into halogen vapor and tungsten, which is then deposited on the filament to make up for the evaporation. Through this recycling process, the service life of the filament is not only greatly extended (nearly 4 times that of the incandescent lamp), but also because the filament can work at a higher temperature, thus obtaining higher brightness, higher color temperature and higher luminous efficiency.
Quality and performance of car lamps and lanterns have important significance for the safety of motor vehicles, our country formulated national standards according to the standards of European ECE in 1984, and the detection of light distribution performance of lamps is one of the most important among them
