Knowing The Several Uses Of Halogen Light Bulbs Over Incandescent Lamps

Published: 19th May 2010
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You do have typical electric light bulbs at home and you see them working every day. Typically, they are made of a tungsten filament encased in a thin and frosted glass. In this glass encasement is not vacuum but a nonreactive gas which is either nitrogen or argon. As electric current runs through the thin filament, it heats up the thin wire. The temperature gets extremely high, about 2,500ÂșC and the thin tungsten wire glows white hot. This process is known as incandescence, and light bulbs that undergo this kind of process are called incandescent bulbs.

Incandescent bulbs are not quite efficient, releasing a great deal of heat and lasting approximately a thousand hours before getting busted. These lamps release too much heat for the light they produce and this means that much of the electric energy is being converted to heat, which is a waste energy, instead of light. Since the major purpose of lamp is to generate light, thermal energy is useless.

Aside from generating so much heat, what contributes to the low efficiency of incandescent lamps is their typically short lifespan due to the rapid burning out of the tungsten filament. In extremely high temperatures, some of the tungsten atoms leave the filament and become deposited on the inner walls of the glass bulb and cause darkening, further lowering the efficiency of the lamp, as the darkened glass bulb reduces light emission. The tungsten filament does not vaporize uniformly. Instead, evaporation occurs on weak spots, where vaporization of tungsten occurs more rapidly. Finally, a break occurs in this region and the light bulb gets busted.

The difference between a halogen lamp and an incandescent one is that the former is better in many aspects. Although both have the same key factor, the tungsten filament, both have different features. Halogen light bulbs are smaller than incandescent bulbs to concentrate heat in a smaller space. The glass encasing is also different because it is infused with quartz which resists temperature extremes. If the bulb were made from glass alone and it's too close to the filament that is hot, it can melt or burst instead of withstand the extreme heat.

The name halogen lamp comes from another key element found inside the glass bulb. While typical bulbs contain an inactive gas like argon or nitrogen, halogen bulbs contain a halogen gas, such as iodine, inside the bulb.

The role of the halogen gas inside the bulb is crucial to its lifespan, as it prevents deposition of the vaporized tungsten atoms onto the inner glass walls of the bulb. Instead, the atoms combine with halogen gas and this process prevents darkening of the glass bulbs. Tungsten atoms are deposited onto the filament once again. This repetitive process prolongs the life of the tungsten filament and therefore the life of the lamp as a whole. This is why these types of light bulbs are able to last longer than ordinary bulbs and can withstand higher temperatures. With the same energy input as an incandescent bulb, a halogen bulb burns with greater intensity, signifying efficiency.

However, because the quartz bulb is so close to the glowing filament, it gets extremely hot too which is a reason you should be cautious when handling halogen lamps at work. Halogen lamps operate with optimum efficiency at expectedly extreme temperatures and, because of this, they can create fire hazard. This is why safety codes for such bulbs require them to be protected by grille or a special housing fixture to avoid direct contact with curtains and flammable materials. Also since the quartz bulb releases UV-B rays, too much skin exposure to halogen lamps can cause sunburn-like symptoms. This is why some bulbs are coated with UV-B filter to reduce radiation emission.

Jo is a writer for 'Litelec' (, a UK company that specializes in the distribution of electric light bulbs, light fixtures, electrical accessories and associated products for home and industrial usage which they trade at vastly reasonable prices. If you wish to reduce your electricity costs and at the same time contribute to the protection of the environment then start by using halogen light bulbs at home and if you have other cheap light bulbs requirement then take a look at Litelec.

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