The difference between incandescent lamps and fluorescent lamps is the reason why incandescent lamps turn black over time?
I. How to distinguish between incandescent lamps and fluorescent lamps?
Fluorescent lamps are gas discharge light sources and are cold light sources. The circuit is broken at the beginning because the lamp gas does not conduct electricity. The high voltage generated by the ballast excites the mercury vapor discharge of the lamp tube, and the electrons hit the phosphor to emit light.
Incandescent lamps rely on metal wires to generate heat and then emit light. Like red-hot iron glowing. So incandescent lamps are not cold light sources.
Second, what is the reason for the blackening of incandescent lamps?
It is a common phenomenon that incandescent lamps turn black after being used for a long time. The blackening of incandescent lamps not only affects lighting, but also makes people worry about its safety. Incandescent lamps will turn black after being used for a long time because the tungsten filament sublimates and evaporates.
The tungsten filament glows in the incandescent lamp. The tungsten filament can remain stable at high temperature without melting, but directly sublimates into gas. After the lamp is turned off, the temperature drops and the tungsten The gas re-condenses into a solid and covers the inner wall of the bulb. Because tungsten is a black solid, after the incandescent lamp is used for a long time, the tungsten accumulates repeatedly on the inner wall of the lamp, and the bulb will turn black.
Incandescent lamps have a lifespan. Generally, after blackening, the lifespan will not be long. Black light bulbs will affect the quality of lighting, and they are not beautiful, so it is better to use them as soon as possible. Replacement, especially in conspicuous places, should be replaced as soon as possible in places that need good lighting, so as to avoid the sudden failure of the light bulb without a spare light bulb, which will affect normal lighting and life and cause various inconveniences.
The life of an incandescent lamp is related to the temperature of the filament, because the higher the temperature, the easier the filament is to sublimate (tungsten directly becomes tungsten gas). Easily blown, thus ending the life of the lamp. Therefore, the higher the power (wattage) of the incandescent lamp, the shorter the lifespan.
