high-intensity discharge

Decoding ANSI Codes

An ANSI code is a series of letters and/or numbers that can be found on High-Intensity Discharge (HID) and Halogen lamps and ballasts. While ANSI coded lamps are slowly being phased out in favor of LED systems, ANSI codes are still useful when matching HID lamps with ballast or vice versa. The ANSI code gets its name from the American National Standards Institute and is used across all industries to ensure uniform identification and performance among commercial products. Essentially, ANSI codes allow one to tell at a glance what the product is and its intended usage. This article will discuss all of the meanings of ANSI codes in lighting and why they are useful to consumers and manufacturers alike.

Ceramic Metal Halide Lamps

Ceramic metal halide (CMH) lamps are a high-intensity discharge (HID) lamp similar to traditional metal halide lamps. Metal halide lamps use a combination of pressurized gasses, salts, and metals inside the glass bulb of the lamp to produce light. An electrical current is introduced by an arc tube within the lamp. An arc tube is the ignition source found at the center of all HID lamps. These use an electrical current to heat up and vaporize the materials inside the bulb; producing a wide range of ultraviolet (UV) wavelengths. This creates both visible light and UV radiation similar to that produced by the sun. For this reason, the bulbs of metal halide lamps are covered in a protective layer, known as luminaire, which allows only the desired wavelengths of light to escape. This broad spectrum of light is one of the desirable qualities of metal halide lamps, particularly CMH lamps. Unlike metal halide lamps which use an arc tube made of quartz, CMH lamps use ceramic arc tubes. This seemingly minor change in construction allows for ceramic arc tubes to reach higher operating temperatures than quartz ones. The higher temperatures allow for better efficiency, less maintenance, and a broader spectrum of light.