4.5 Flashcards
A _____ is a device that generates light.
Lamp
This kind of lamp provides light source by incandescence, which is the emission of light caused by heating the filament.
Incandescent Lamps
This category can be divided into two more sub-categories: low-pressure lamps, and high-intensity discharge (HID).
Gaseous Discharge Lamps
Gaseous discharge lamps made of fluorescent lamps and are low-pressure sodium lamps
Low-pressure discharge
Gaseous discharge lamps that are high-pressure sodium lamps
It is a complete lighting unit which consists of lamps, lamp sockets, any lenses, refractors, or louvers, any ballasts, and the housing.
Luminaire
____________ is the measure of the perceived power of light expressed in lumens (lm).
Luminous flux
Defined as the quantity of light given out through a steradian by a source of one candela of intensity radiating equally in all directions.
Lumen
is the SI unit of luminous intensity
Candela (cd)
The ratio of the light output of a light source to the electrical energy consumed to produce the light source.
Luminous efficacy
The color of light emitted by a light source correlates to the ___________ of the emitting source.
temperature
The _______________ is a method of numerically comparing the color distribution of a light source to a reference lamp.
color rendering index (CRI)
A __________________________ curve is a graphic representation of the quantities of light emitted by a lamp by wavelength components.
spectral power distribution
The rated life of a lamp is its _________ life expectancy, expressed in hours.
median
As lamps operate the luminous flux (lumen output) will decrease. Incandescent lamps will degrade to about ____ of the lamp’s initial lumen output. _________ in a fluorescent lamp, and _______ in a HID lamp.
85%, 60%-80%, 50%-70%
