8 Terms
Contributors in Lighting
Lighting
lamp current crest factor (LCCF)
Construction; Lighting
The peak lamp current divided by the RMS (average) lamp current. Lamp manufacturers require <1.7 for best lamp life. An LCCF of 1.414 is a perfect sine wave.
reflector
Construction; Lighting
The part of a light fixture that shrouds the lamps and redirects some light emitted from the lamp.
rapid start (RS)
Construction; Lighting
The most popular fluorescent lamp/ballast combination used today. This ballast quickly and efficiently preheats lamp cathodes to start the lamp. Uses a "bi-pin" base.
lux (LX)
Construction; Lighting
The metric unit of measure for illuminance of a surface. One lux is equal to one lumen per square meter. One lux equals 0.093 footcandles.
work plane
Construction; Lighting
The level at which work is done and at which illuminance is specified and measured. For office applications, this is typically a horizontal plane 30 inches above the floor (desk height).
footcandle (FC)
Construction; Lighting
The English unit of measurement of the illuminance (or light level) on a surface. One footcandle is equal to one lumen per square foot.
glare
Construction; Lighting
The effect of brightness or differences in brightness within the visual field sufficiently high to cause annoyance, discomfort or loss of visual performance.
