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Canadian Standards Association (CSA)
An organization that writes standards and tests lighting equipment for performance as well as electrical and fire safety.
Canadian provincial laws generally require that all products sold for consumer use in Canada must have CSA or equivalent
approval.
Candela (cd)
The measure of luminous intensity of a source in a given direction. The term has been retained from the early days of
lighting when a standard candle of a fixed size and composition was defined as producing one candela in every direction.
A plot of intensity versus direction is called a candela distribution curve and is often provided for reflectorized lamps
and for luminaires with a lamp operating in them.
Candlepower
An obsolete term for luminous intensity; current practice is to refer to this simply as candelas.
Capacitor
Device in ballast that stores electrical energy.
Center Beam Candlepower (CBCP)
Refers to the luminous intensity at the center of the beam of a blown or pressed reflector lamp (such as a PAR lamp).
Measured in candelas.
Centigrade (C)
Celsius temperature scale where 0°C = 32°F and 100°C = 212°F.
Ceramic Metal Halide (CMH®)
A type of metal halide lamp that uses a ceramic material for the arc tube instead of glass quartz, resulting in better
color rendering (>80 CRI) and improved lumen maintenance.
Chromaticity
the aspect of color that includes consideration of its dominant wavelength and purity.
Coefficient of Utilization (CU)
In general lighting calculations, the ratio of the luminous flux (lumens) from a luminaire received on the work-plane
to the lumens emitted by the luminaire's lamps alone.
Coil
Windings of copper or aluminum wire around the core in electromagnetic ballast that transforms the voltage from
input to output.
Color Rendering Index (CRI)
An international system used to rate a lamp's ability to render object colors. The higher the CRI (based upon a 0-100 scale)
the richer colors generally appear. CRI ratings of various lamps may be compared, but a numerical comparison is only valid
if the lamps are close in color temperature. CRI differences among lamps are not usually significant (visible to the eye)
unless the difference is more than 3-5 points.
Color Temperature (Correlated Color Temperature - CCT)
A number indicating the degree of "yellowness" or "blueness" of a white light source. Measured in Kelvin (K),
CCT represents the temperature an incandescent object (like a filament) must reach to mimic the color of the lamp.
Yellowish-white ("warm") sources, like incandescent lamps, have lower color temperatures in the 2700K-3000K range;
white and bluish-white ("cool") sources, such as cool white (4100K) and natural daylight (6000K), have higher color
temperatures. The higher the color temperature the whiter, or bluer, the light will be.
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 candalabra screw bases for easy replacement of
incandescent lamps.
Core
Component of electromagnetic ballast that is surrounded by the coil and comprised of steel laminations or solid ferrite
material.
Core & Coil Ballast
Another term for electromagnetic ballast.
Crest factor
Ratio of peak lamp current to RMS (average) lamp current.
CSA-E
Marking on ballast that shows compliance with Canadian Ballast Energy Law.
Current
A measure of the flow of electricity, measured in amperes (A)
Cut-off Angle
(of a luminaire) the angle from the vertical at which a reflector, louver or other shielding device cuts off direct visibility of a light source. It is the complementary angle of the shielding angle.
Cycling
See 'Ballast Cycling'.
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