In fact before the birth of carbon filament incandescent lamp

In fact before the birth of carbon filament incandescent lamp, people try to do all kinds of refractory metal filament incandescent lamp came in after the search for the ideal state is to spare no effort in the filament. finally in the 20th century 9th year, the Americans found the performance excellent Keli Qi material mmm tungsten filament. tungsten has many notable features, it more than any other to be high melting point metal elements, and it is less evaporation when heated , so the materials for the filament, tungsten is an ideal fit. with the production of tungsten filament incandescent lamp as it is lighting a milestone in the history of technology.
tungsten incandescent lamp made with the introduction of kerosene, gas lamps, competition in the petrol lamp to obtain a decisive victory; tungsten applications effectively promoted the development of electric lighting industry, has opened a new era of electric lighting technology. .improvements in incandescent lamps are not complacent and .1913, the Langmuir first time to the glass bulb filled in nitrogen, which is the second from the carbon filament to tungsten filament, the incandescent lamp is another important innovation.