What is hid technology?

HID (High Intensity Discharge) is a technology that substitutes the traditional wolfram filament in halogen bulbs with a sealed capsule of xenon gas.

The technology in high intensity discharge lighting is in some ways similar to fluorescent technology: an arc is established between two electrodes in a gas-filled tube which causes a metallic vapour to produce radiant energy. However, in the case of HID technology, a combination of factors shifts the wavelength of much of this energy to within the visible range, so light is produced without the need for phosphors. In addition, the electrodes are only a few centimetres apart (at opposite ends of a sealed “arc tube”) and the gases in the tube are highly pressurized. This allows the arc to generate extremely high temperatures, causing metallic elements floating inside the bulb to vaporize and release large amounts of visible radiant energy. There are three main types of HID lamps: mercury vapour, metal halide and sodium. The names refer to the elements that are added to the gases in the arc stream which cause each type to have somewhat different color characteristics and overall lamp efficiency.

Like any gaseous discharge light source, HID lamps have a number of specific electrical requirements that must be supplied by a ballast. HID lamps require a warm-up period to achieve full light output. HID lamps are an ideal choice for applications where safety is a concern.