What is a fluorescent lamp? What are fluorescent lights?
Because most of the energy consumed by fluorescent lamps is used to produce ultraviolet light, fluorescent lamps are much better than incandescent and halogen tungsten lamps, so they are energy saving electric light sources at present. The fluorescent lamp is about 0.8Pa pressure mercury vapor discharge, under the action of electric field in the discharge process, the valence electrons of mercury atoms continuously from the original state is excited into an excited state, and excited state of spontaneous returns to the ground state, the valence electron is converted to electromagnetic radiation, and radiation at the beginning 3.7nm UV (ultraviolet also about 10% 85nm). The phosphor on the inner wall of the butcher's carrier tube absorbs ultraviolet light from the 353.7nm and transforms it into visible light. Electrodeless fluorescent lamp is electrodeless lamp, it cancels the filament and the electrode of the traditional fluorescent lamp, using the principle of electromagnetic coupling, the mercury atoms from the original state into the excited state, the luminescence principle and system of fluorescent lamp is similar, is now the new energy-saving light source. The utility model has the advantages of long service life, high luminous efficiency, good color rendering, etc..
The traditional fluorescent lamp type fluorescent lamp and electrodeless fluorescent lamp, traditional fluorescent lamp is a low pressure mercury lamp, mercury vapor is the use of low pressure in the discharge process of ultraviolet radiation, so that the phosphors emit visible light emitting principle, so it belongs to low pressure arc discharge light source. The traditional fluorescent lamp is equipped with two filaments. The filament is coated with electronic emission materials, three yuan carbonate (barium carbonate, strontium carbonate and calcium carbonate), commonly known as electronic powder. The alternating filament acts as a cathode and anode under alternating voltage. The inner wall of the lamp tube is coated with phosphor powder. The tubes are filled with argon at 400Pa-500Pa pressure and a small amount of mercury. After discharge, the liquid mercury evaporates into mercury vapor at a pressure of 0.8 Pa. In the electric field, the mercury atoms continuously from the original state is excited into the excited state, then spontaneous transitions to the ground state, and the radiation wavelength of 253.7nm and 185nm (the peak value of ultraviolet wavelength is 253.7nm, total radiation energy 70-80%; peak wavelength is 185nm, accounting for about 10% of the total radiant energy), to the release of excess energy. The fluorescent powder absorbs ultraviolet radiation and emits visible light. Fluorescent powder is different, the light is also different, that is, fluorescent lamps can be made white and various colors reasons.
The fluorescent tube is a glass tube, the inner wall is coated with a layer of fluorescent powder (magnesium tungstate, calcium tungstate, zinc silicate, etc.), different phosphors can emit light of different colors. The lamp tube is filled with thin inert gas (such as argon gas) and mercury vapor, and both ends of the lamp tube have a filament made of tungsten, and the filament is coated with an oxide which is easy to emit electrons after being heated. When the filament passes through the current, the filament in the lamp tube emits electrons, and the temperature in the tube is increased, and the mercury is evaporated. Along with the gradual rise in temperature in the tube, mercury vapor free, inert gas molecular collision when mercury vapor discharge, arc discharge, it radiates invisible ultraviolet light, visible light fluorescent powder in the inner wall of the tube after UV excitation.
