Упрощенная HTML-версия
XII.3
Glossary
Colour Rendering Index (CRI)
An international system used to rate a lamp’s
ability to render object colours. The higher the
CRI (based upon a 0-100 scale) the richer colours
generally appear. CRI ratings of various lamps
may be compared, but a numerical comparison
is only valid if the lamps are close in colour
temperature. CRI differences among lamps are
not usually significant (visible to the eye) unless
the difference is more than 3-5 points.
Colour Rendering Indicator
Draws attention to the fact that this is a lamp
with high colour rendering, which helps objects
and persons illuminated to appear more true
to life.
Colour Temperature (Correlated Colour
Temperature - CCT)
A number indicating the degree of “yellowness”
or “blueness” of a white light source. Measured
in Kelvins, CCT represents the temperature an
incandescent object (like a filament) must reach
to mimic the colour of the lamp. Yellowish-white
(“warm”) sources, like incandescent lamps, have
lower colour temperatures in the 2700K-3000K
range; white and bluish-white (“cool”) sources,
such as cool white (4100K) and natural daylight
(6000K), have higher colour temperatures. The
higher the colour temperature the whiter, or
bluer, the light will be (See CHROMATICITY).
Compact Fluorescent Lamp (CFL)
The general term applied to fluorescent lamps
that are single-ended and that have smaller
diameter tubes that are bent to form a compact
shape. Some CFLs have integral ballasts and
medium or candelabra screw bases for easy
replacement of incandescent lamps.
ConstantColor™
A GE registered name for lamp families that
show very little colour shift over life, such as
GE’s Precise™ MR16 lamps and GE’s ceramic
metal halide (CMH) lamps.
Coolbeam
(See DICHROIC REFLECTOR)
Cool White
A term loosely used to denote a colour
temperature of around 4100 K or higher. The
Cool White (CW) designation is used specifically
for T12 and other fluorescent lamps using
halophosphors and having a CRI of 62.
Core
Component of electromagnetic ballast that is
surrounded by the coil. Core is comprised of
steel laminations or solid ferrite material.
Core & Coil Ballast
A ballast that uses a “Core & Coil” assembly
to operate fluorescent or HID lamps. Refers to
copper or aluminum windings on a steel core.
Cosine-Corrected
An illuminance meter that measures the light
level correctly irrespective of the angle the light
is coming from. (See ILLUMINANCE METER)
Cost of Light
Usually refers to the cost of operating and
maintaining a lighting system on an ongoing
basis. The 88-8-4 rule states that (typically) 88%
is the cost of electricity, 8% is labor and only
4% is the cost of lamps.
covRguard™
A lamp encased by a plastic sleeve or coating
to help contain glass fragments if the lamp
breaks.
Crest Factor (Max Current)
The ratio of the peak lamp current to average
lamp operating current (RMS). The lower the
current crest factor is, the gentler the ballast is
on the lamp.
Current Type (AC/DC)
Whether the operational voltage is based on
Alternating Current or Direct Current .
D
Daylight Harvesting
Lighting design for building interiors that
makes of daylight as a way of reducing energy
consumption.
Daylight Lamp
A lamp resembling the colour of daylight ,
typically with a colour temperature of 5500 K
to 6500K.
Declaration of Conformity (DoC)
A self-declaration of a product on its compliance
to the Electromagnetic Compatibility Directive
and the Low Voltage Directive and it can bare CE
conformity marking (EU).
Dichroic Reflector (or Filter)
A reflector (or filter) that reflects one region of
the spectrum while allowing the other region(s)
to pass through. A reflector lamp with a dichroic
reflector will have a “cool beam” i.e. most of
the heat has been removed from the beam by
allowing it to pass through the reflector while
the light has been reflected.
Die
See Chip.
Dimmable
Whether or not the lamp lumens can be varied
while maintaining reliability.
Dimmer, Dimming Control
A device used to lower the light output of a
source, usually by reducing the wattage it
is being operated at . Dimming controls are
increasing in popularity as energy conserving
devices.
Discharge Lamp
A lamp where light is emitted from an electrical
discharge between two electrodes as opposed to
a filament lamp. Examples are: Fluorescent lamps
and HID (High Intensity Discharge) lamps like
Metal Halide, Mercury and High Pressure Sodium.
All discharge lamps require some kind of current
limiting device, e.g. a ballast , to operate them.
Driver
Control gear for LED-based products. Can be
either constant current or constant voltage. For
LED lamps the driver is often integral (see ‘Self-
Ballasted Lamps’).
E
Eccentricity (Maximum)
In High Intensity Discharge lamps the Bulb to
Arc Angle is the angle off of center between
electrodes and bulb. The Bulb to Base Angle
is the angle off of center that the bulb is from
the base.
Edison Award
An annual competition where lighting designers
submit their best projects. The entries are
judged by an international panel and awards
are presented at a banquet accompanying
Light Fair, the North American trade show for
the lighting industry.
Efficacy
A measurement of how effective the light
source is in converting electrical energy to
LUMENS of visible light . Expressed in LUMENS-
PER-WATT [LPW] this measure gives more
weight to the yellow region of the spectrum and
less weight to the blue and red region where the
eye is not as sensitive.