Glossary

BALLAST FACTOR
Ratio of a lamp’s light output on ballast compared to the lamp’s rated light output. The higher the ballast factor, the more light delivered.

CIRCLE E BALLAST
Indicates special EPACT compliant version of ballast. Check the laws and codes for specific applications.

COLOR RENDERING INDEX
CRI-indicates how true to color lighted objects appear. A higher number means truer color. The CRI creates light sources on a scale of 0 to 100. The higher the CRI the more vibrant or close to natural the colors the objects appear.

COLOR TEMPERATURE OR CHROMATICITY
The appearance of the light that comes from a light source. The color temperature is measured in Kelvin or “k”. The higher the color temperature, the visually cooler or bluer the light appears.

ELECTRONIC BALLAST
A ballast that utilizes electronic components to transform current at high frequency to operate fluorescent or discharge lamps.

FOOTCANDLE
The measurement of the amount of light reaching the surface. Footcandles are measured in lumens per square foot.

LAMP EFFICACY
Different lamp types have different abilities to convert electrical power (watts) into visible light (lumens). The quality of light emitted is divided by the input power to determine the lamps efficacy. This is expressed as lumens per watt LPW.

LIFE
How long on average a bulb is estimated to last. The number of burning hours on average after which 50% of representative groups of lamps in tests under controlled burning conditions and at a specified number of burning hours per start have failed.

LPW
Lumens per watt is a measure of energy efficiency. Fluorescent lamps are very energy efficient and emit up to 100 lumens per watt.

LUMENS
Bulb brightness. A higher number means brighter light. Fluorescent lamp lumens decrease over its life.

MAGNETIC BALLAST
A ballast that uses core and coil assembly to transform electrical current to start and operate fluorescent lamps.

OCTRON BALLAST
A ballast designed to operate 1” diameter, T8 fluorescent R.S. lamps. It is not compatible with T12 or preheat lamps.

POWER FACTOR
The ratio of power(watts) to volt-amps of the ballast. The power factor ratio may be used to determine how efficiently total input power is being used.