halogen lamp

halogen lamp

 or tungsten-halogen lamp

Incandescent lamp with a quartz bulb and a gas filling that includes a halogen. It gives brilliant light from a compact unit. The halogen combines with the tungsten evaporated from the hot filament to form a compound that is attracted back to the filament, thus extending the filament's life. The evaporated tungsten is also prevented from condensing on the bulb and darkening it, an effect that reduces the light output of ordinary incandescent lamps. First used in the late 1960s in motion-picture production, halogen lamps are now also used in automobile headlights, underwater photography, and residential lighting.

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tungsten-halogen lamp

A tungsten-filament incandescent lamp which is filled with a gas containing halogens; the envelope, made of quartz or other material that can be subjected to high-temperature, is small compared with standard lamps of equivalent wattage; formerly known as quartz-iodine lamp.