What shines in the electric lamp is the tungsten filament, which can remain stable at a very high temperature without melting, but directly sublimates into gas. When the lights are turned off, the temperature drops, and the tungsten gas condenses into a solid again and covers the inner wall of the bulb. Because tungsten is a black solid, after the incandescent lamp is used for a long time, tungsten accumulates repeatedly on the inner wall of the lamp, and the bulb will turn black.
Electric lamps have a long life. Generally, after blackening, their life will not be long. Black bulbs will affect the lighting quality, and they are not beautiful. Therefore, it is better to replace them as soon as possible, especially in conspicuous places, where good lighting is needed, so as to avoid the sudden failure of bulbs without spare bulbs, which will affect normal lighting and life and cause various inconveniences.
The life of the lamp is related to the temperature of the filament, because the higher the temperature, the easier it is for the filament to sublimate (tungsten directly becomes tungsten gas). When the tungsten filament sublimates to be thinner, it is easy to burn out after being electrified, thus ending the life of the lamp. Therefore, the greater the power (wattage) of an electric lamp, the shorter its life.
Choose energy-saving lamps: fluorescent lamps save more electricity than incandescent lamps. The brightness of 20-watt fluorescent lamp is even better than that of 40-watt incandescent lamp. 4 watts can completely replace 20 watts of ordinary fluorescent lamps and 20 watts of ordinary energy-saving lamps).
Make full use of reflection and reflection: if the lamp is equipped with a suitable reflector, the illumination can be improved. The illumination can also be improved by about 20% by using the reflection of indoor walls and white walls.
Always keep bulbs and lampshades clean to ensure the highest lighting and light reflection effect.
The installation height should be appropriate. For example, a 20-watt fluorescent lamp, if installed 1 meter high, has an illumination of 60 lux; 0.8 meters high is 93.75 lux. Lowering the height properly can reduce the wattage and save electricity. (Only businesses with LED departments can do it. If the installation is 2 meters high, the illumination is about 200 lux; 3 meters high is about 96,200 lux. It is often useful to use LED lighting products to save energy.