HID Bulbs

High Intensity Discharge (HID) Lamps

There are many types of HID (Gas Discharge) lamps, they all produce light by means of an electric arc between two electrodes within a quartz arc tube.  This tube is filled with gas and metals. As the metal heats, the presence of the evaporated metals increases the intensity of visible light produced by the arc.

All HID lamps require a ballast in order to provide the initial ignition start to the lamp and regulate the current for constant operation.
Types of HID Lamps:
  • Metal Halide
  • Pulse Start Metal Halide
  • High Pressure Sodium
  • Low Pressure Sodium
  • Mercury Vapor
Metal Halide
Preferred in most outdoor applications because of the crisp white light, they are the most popular of the HID bulbs.  The wattage for Metal Halide bulbs is 35 to 1500.  They are typically the only type of HID bulb you will see used in indoor applications.  Standard Metal Halide lamps use a Probe Start Ballast.
Pulse Start Metal Halide
The ballast for this type of metal halide uses a high voltage ignitor that sends electronic pulses to ignite the lamp.  This type of ignition will extend that life of the lamp by up to 50%.
High Pressure Sodium
The HPS lamp is the second most efficient light source available (LED is the first).  These lamps are very popular in municipalities that have adopted “Dark Sky” practices for their street lighting.  Although still in production, the color of the HPS lamp (2300K), and the CRI (85) makes this lamp somewhat outdated for general use.  
Low Pressure Sodium
Low Pressure Sodium (SOX lamps) are an unpopular light source because of their yellow color and almost monochromatic visual effect.
The last manufacturer to produce these lamps discontinued production in 2017.
Mercury Vapor
These HID lamps are very efficient and long-lasting.  One of the first types if high intensity discharge lamps to be massed produced, they are becoming obsolete, having been replaced by metal halide lamps, and now LED.