High Intensity Discharge (HID) lighting technology replaces the filament of the light bulb with a capsule of gas. The light is emitted from an arc discharge between two closely spaced electrodes hermetically sealed inside a small quartz glass tubular envelope capsule. To operate, they require ballasts, which supply proper voltage and control current. The amount of light produced is greater than a standard halogen bulb, while consuming less power, and more closely approximating the color temperature of natural daylight.

In all High Intensity Discharge lamps, passing a current through a metal vapor produces light. Free electrons colliding with an atom in the vapor momentarily knock an electron into a higher orbit of the atom. When the displaced electron falls back to its former level, a quantum of radiation is emitted. The wavelength of radiation depends on the energy zone of the disturbed electron and on the type of metal vapor used in the arc tube.

Although it produces 5% of its output when first ignited, the HID light requires a few seconds (usually 15-20) to come up to full output. Also, if power to the lamp is lost or turned off, the arc tube must cool to a given temperature before the arc can be re-struck and light produced. Xenon-Bulbs HID lights only require a brief (15-30 second) cooling period before they can be re-lit.

What are the advantages of Xenon Bulbs HID lights over conventional halogen primary lights?

HID lighting has several advantages over conventional halogen primary lights:

• More light output. Xenon-Bulb's 18 Watt HID light source produces approximately the same lumens at the light source as a 55 Watt halogen bulb at a three to five times the halogen's efficiency. The 10 Watt HID only produces ~500 lumens, but thanks to its true 6000K color temperature it appears almost as bright as a 55 Watt halogen bulb when in use. The HID lamp's lumens per watt (LPW) efficacy is roughly six to eight times that of an incandescent lamp.

• Whiter light. The color temperature of HID lighting more closely approximates the color temperature of natural daylight than does a halogen system, which appears yellowish in comparison. We use the term "correlated color temperature" to indicate that the light appears as if the discharge lamp is operating at a given color temperature-- traditional measurements of color temperature are drawn from the properties of the metal used in the bulb's filament. Typical color temperatures are 2800K (incandescent), 3000K (halogen), 4100K (cool white or SP41 fluorescent), and 5000K (daylight-simulating fluorescent colors). Both of the Xenon-Bulbs HID lights produce a light with a color temperature approaching or above 5000K. A white light has a perceived brightness which may equate to the higher stated efficacies—i.e., although an HID lamp might have equivalent lumens as a higher wattage halogen bulb, the HID will appear brighter and more pleasing to the eye than the output of a halogen lamp.

• Longer Service Life. An HID lamp will last, on the average, 3 to 5 times as long as a halogen bulb. In normal use, your Xenon-Bulbs HID should last beyond one thousand ignitions.