The fluorescent tube is equipped with filaments at both ends, and the inner wall of the glass tube is coated with a uniform thin phosphor. After the tube is pumped into a vacuum 103-104 mm mercury column, a small amount of inert gas is filled into the tube, and a small amount of liquid mercury is injected at the same time. The inner wall of the lamp tube is coated with phosphor. When the gas between the two filaments conducts electricity, it emits ultraviolet light, which makes the phosphor emit soft visible light.
Blackening at both ends of the lamp: tungsten wire sublimation directly into tungsten gas, these tungsten gases encounter lower temperature lamp wall and condensation on the lamp wall and blackening, when tungsten wire sublimation to a relatively thin, it is easy to burn after electrification.
Disadvantages of fluorescent lamp: (1) There are many accessories of fluorescent lamp, and there are many chances of failure.
(2) Fluorescent lamps are more expensive than tungsten filament incandescent lamps.
(3) The power of fluorescent lamps cannot be very high.
(4) Fluorescent lamp is the appearance of flickering stroboscopic
