ANSI Code
An ANSI code is either an alpha or numeric designation that ensures certain specifications such as wattage voltage shape and base. ANSI stands for American National Standards Institute. This organization develops voluntary guidelines and produces performance standards for the electrical and other industries.

Average Rated Life
An average rating, in hours, indicationg when 50% of a large group of lamps have failed, when operated at nominal lamp voltage and current; manufacturers use 3 hours per start for fluorescent lamps and 10 hours per start for HID lamps when performing lamp life testing procedures; every lamp type has a unique mortality curve that depicts its average rated life.

Ballast
A device used with an electric discharge lamp to obtain the necessary circuit conditions (voltage, current and waveform) for starting and operating; all fluorescent and HID light sources require a ballast for proper operation.

Base
The lamp base mechanically holds the lamp in place in the application. The lamp base directly or indirectly conducts electricity from the circuit to the lamp and can be designed to dissipate heat.

Beam Angle
The angle between the two directions for which the intensity (candlepower) is 50% of the maximum intensity as measured in a plane through the nominal beam centerline (center beam candlepower).

Beam Spread
In any plane, the angle between the two directions in the plane in which the candlepower is equal to a stated percent of the maximum candlepower in the beam.

Candela (cd)
International unit (SI) of luminous intensity of a light source in a specific direction.

Center Beam Candlepower (CBCP)
Intensity of light produced at the center of a reflector lamp beam, expressed in candelas.

Color Rendering Index (CRI)
The method that indicates how colors will look under a given source. A color rendering index (CRI) number is assigned to a light source based on its ability to make pigments look as they would under certain test sources when compared to other sources having the same color temperature.

Color Temperature
Color temperature, which is measured in Kelvin (K) indicate its degree of warmth or coolness. “Warm” light sources have a low color temperature (2000K-3000K) and feature more light in the red/orange/yellow range. Light with a higher color temperature (>5000K) features more blue light and is referred to as “cool”.

Compact Fluorescent Lamp (CFL)
Compact fluorescent lamp, also known as a compact fluorescent light Bulb, is a low-energy light bulb. Many CFLs are designed to replace an incandescent lamp and can fit in the existing light fixtures formerly used for incandescents.