Luminaire Flashcards
What is a Luminaire?
A luminaire is a complete lighting unit consisting of lamps, wiring channel, reflectors, lens, diffusers, and control gear (such as ballasts for gas discharge lamps) where necessary
What is the purpose of the luminaire?
To provide the distribution of light
Luminaires are classified on the basis of how they distribute light vertically- either_______or________.
Upwards, downwards
The five method of light disbursement are:
- Direct
- Indirect
- Semi-direct
- Semi-indirect
- Diffused
The percentage of total lumen emitted by the luminaires compared to total lumens generated by the lamp alone.
Luminaire efficiency
The percentage of the initial lamp lumens that reach the task area to produce illumination.
Coefficient of utilization
The selection of luminaires is usually made based on:
Luminaire efficiency and Coefficient of utilization
The choice of the light source for luminaires is:
- Incadescent
- Fluorescent
- high intensity discharge (HID)
- low-pressure sodium (LPS)
- LED
The two of the main causes of light loss up to 50% with time are:
- Lamp Lume depreciation
- Luminaire Dirt Depreciation
The accumulation of dirt on lamps and fixtures can cause light losses of 30% or more
Luminaire Dirt Depreciation
Who invented and patented the incandescent bulb?
Joseph Swan
What are the advantage of incandescent bulbs?
- Affordable
- Compact
- produce light with warm color tone
The higher the efficacy, the ________ the life expectancy
lower
The higher the operating temperature of the filament, the ______ the light output, but the _______ the life span of the lamp
Higher, shorter
Quartz glass is used with tungsten-halogen lamps because…….
it can withstand very high temperatures.
The size and shape of a bulb is designated by a
Code
T-10 indicates a tubular bulb having a diameter of
11/4”
G-57 indicates a globular bulb having a diameter of 57
71/8”
The three glass used for bulb lamps may be:
Clear, Diffuse, or Colored.
_________ reduces the brightness of the light source by
effectively increasing the surface area of the bulb.
Diffuse glass
__________ bulbs are used to produce different colors of light.
Colored glass
_________ is ideal where good optical control is required as in
overhead projectors or spotlights
Clear glass
Bulbs of 300 W or above are available with _______ bases
Mogul
The most commonly used base for a general service lamp is the ________.
Edison base
Typical sizes of lamp bases are:
mogul, medium, intermediate and candelabra
The ________ base, which accommodates lamps from 7.5 W up to and including 300 W, is the most common
medium
Low-wattage indicator lamps and decorative lights use ________ or _________ bases.
candelabra, intermediate
_________ are used for floodlighting where better heat radiation is possible.
These lamps generally have wattages of 500 W or more.
Biposts
_________ lamps have a _________ efficacy (lumen output per watt) than low-wattage lamps of the same voltage
High-wattage, higher
Three 50 W lamps produces more light than one 150 W lamp. True of False?
False. One 150 W lamp produces more light than three 50 W lamps
High voltage lamps normally have a longer service life than 120 V lamps. True or False?
False. Low voltage lamps normally have a longer service life than 120 V lamps
Higher filament temperatures produce greater efficacy but have a reduced service life. True or false?
True
Over-voltage operation results in increased wattage, __________ output and_________.
More light, reduced life
An operation has the opposite effect, producing decreased wattage, less light output and longer service life.
Under voltage
he tungsten-halogen lamp is also called a
quartz-halogen lamp or quartz-iodine lamp.
The four basic dimmer functions are:
-Adjustment
-Pre-Sets
-Remote / 3-Way
-Indicator Light
