HID vs Xenon
HID stands for High Intensity Discharge which are arc lamps. They are popular light sources and have widespread usage in applications where high illuminance over an area is needed. Xenon is an inert gas used in the tube of HID; hence called Xenon Lamps or Xenon arc lamps.
More about HID
The HIDs are a type of arc lamp. As the name implies, HID lamps generate light by an electric discharge between two tungsten electrodes through a gas contained in a tube. The tube is often made out of quartz or fused alumina. The tube is filled with both a gas and metal salts.
The electric arc between the tungsten electrodes is very intense such that the gases and the metal salts inside the tube instantly turn into plasma. The discharge of electrons in the plasma, excited to a higher energy level by the energy from the arc, give the distinctive light with higher intensity. This is because a higher portion of the electrical energy is converted into light energy in the discharge process. Compared to incandescent and fluorescent lamps, HID lamps are brighter.
Depending on the requirements many kinds of substances are used inside the tube. Specifically, the metal that is vaporized during the operation determines most of the properties of the HID lamps. Mercury was the first used metal and commercially available too. Later the sodium lamps were also produced. Mercury lamp has a bluish light, and the sodium lamps have a bright white light. Both these lamps are used in laboratory equipment as monochromatic light sources.
Later mercury lamps with lesser blue light were developed, but both mercury and sodium lamps are now being replaced by the metal halide lamps. Also, radioactive isotopes of Krypton and Thorium mixed with argon gas are used to improve the characteristics of the lamps. Special protective measures are taken to prevent α and β radiation, when these isotopes are included in the tubes. The arc of these lamps generates a considerable amount of UV radiation and, therefore, UV filters are also used.
HID lamps are used when high intensity of light is required over large expanses. They are typically used in large open buildings such as gymnasiums, warehouses, hangars, and in open areas that need to be illuminated such as roads, football stadiums, parking lots, and amusement parks. HID lamps are also used as headlights of automotive and as light sources in underwater diving.
More about Xenon Lamp
Xenon lamps are HID lamps with xenon gas inside the tube. When the electric arc is created, xenon gas turns into plasma and the electron transition to lower states produces a bright white light, close to the day light.
There are three major types of Xenon lamps.
• Continuous-output xenon short-arc lamps
• Continuous-output xenon long-arc lamps
• Xenon flash lamps
Xenon lamps are used in modern IMAX projectors, to create pure white light that is needed. They are used in automobiles too. They are often used for solar light simulation to the closeness of the spectrum of light given by the xenon lights.
HID vs Xenon
• HID lamps are arc lamps, and produce high intensity light that can be used to illuminate large areas. Xenon lamps are a type of HID lamps where the gas used inside the tube is xenon.