In 1958, a new type of incandescent light bulb was brought in in the market. They named it halogen bulb. It’s efficient in burning brighter and longer as compared to ordinary light bulbs, making it the more advantageous solution in cases when especially bright lights are called for. Since halogen light bulbs burn with more power and live longer, they end up being much more effective as compared to ordinary incandescent lamps.
Halogen-containing light bulbs and incandescent lamps have fairly similar designs, taking into account that the first mentioned were a variation of the second item. Similar to the ordinary incandescent light bulb, a halogen lamp has a tungsten filament which is encased in a bulb. However for the latter, the bulb uses quartz instead of glass. Quartz survives higher temperatures than glass. Therefore, the quartz bulb can be made close to the filament, consequently enabling this kind of lights to be small compared to ordinary light bulbs.
As suggested by its name, halogen lamps contain halogen gas in the bulb encasing. Light bulbs need a nonreactive or inert gas inside the bulb to avoid reaction with the extremely hot tungsten. Incandescent lamps have argon or nitrogen, but the new model has a halogen gas in its place. Ordinarily the halogen gas is iodine.
All light bulbs work by allowing electric current to move through the tungsten filament. Because this kind of filament is a very thin wire, it has increased amount of resistance which is converted to heat the moment current crosses. This temperature increases until the wire glows white hot. Voila! You have a working lamp. However, as the heat causes the filament to light, it is also this particular heat that causes its slow deterioration. Since tungsten is heated up to really high temperatures, it vanishes. Tungsten particles get settled on inner surfaces of the light bulb in regular lamps. But in state-of-the-art lamps with halogen gas, the halogen reacts with tungsten atoms to keep deposition as well as reduce blackening of lamps. Tungsten particles are then re-deposited on the filament making it survive longer.
As mentioned, any halogen lamp can burn brighter than an incandescent light bulb. And since they glow brighter, they shine a lot warmer as well. The quartz encasement is also a lot warmer because of its closeness to the shining filament. This particular heat might be good enough to inflame a flammable product close by. So, as a safety measure, halogen filled light bulbs must be positioned far from flammable and combustible materials. Careful storing of the bulbs needs to be observed to prevent accidents and burns.
Professionals do not recommend clasping halogen bulbs using uncovered hands since this could ruin the quartz surface with oils and salts from your skin. The exposed quartz surface will become a weak spot to reduce the life expectancy of the light bulbs. Hence, the light bulbs must only be handled, soon after being cooled down inside the socket, using gloved hands. If unintentional skin contact was made, the bulb needs to be wiped completely.