What is High Definition Lighting?

How Does HID Lighting Work?




HID, or high definition, lamps are typically required when high levels of light are needed to cover large areas. They are the lights you see at ballgames and theme parks, at stadiums and in gyms. 




There is a high demand for HID lamps because of their efficiency on a wide scale and their ability to clearly cover huge areas.  They come in several versions: mercury vapor lamps, metal halide lamps, and standard high-pressure sodium lights.  




Mercury vapor lamps were the first commercially available high definition lamps (HID). They are swiftly becoming outdated by newer more efficient counterparts like high-pressure sodium lamps and metal halide lamps.




High-pressure sodium lamps generally emit a more yellowish light, but are available with whiter light. They are usually the most efficient, and thus most commonly used, type of HID light. Metal halide lamps produce a beautifully white, natural light, but are also less efficient.




How do HID lamps produce light?







High intensity discharge lamps produce light when the gases inside the fused alumina tube are heated to the point of evaporation. Tungsten electrodes are kept in the alumina tube, and when the metal elements begin to heat up, they strike the tungsten electrodes, creating an arc of light.




Similar to fluorescent lights, HID lamps need a ballast  (a device used to start gas discharge in a lamp and limit the flow of electrical current) to even start producing heat. If they don’t have the ballast, the reaction won’t begin, and there won’t be any light.




What are tungsten electrodes?







Tungsten is a chemical element that is known for its high melting point and robust physical characteristics. It is used widely in electrical applications like lighting because of these properties. It is a hard, non-alloy metal that ranges in color from steel gray to tin white. It is shaped, or “drawn” into the very thin metal wires you see inside a light bulb.




What applications are there for HID lamps?