Definitions. Unless specifically defined below, words and phrases used in this section shall be interpreted to have common English usage, to give effect to the purposes set forth in §
260-86A above and to provide reasonable application of this section. As used in this section, the following terms shall have the meanings indicated, unless a different meaning clearly appears from the context:
AFG
Above finished grade.
BUG RATING
The IES designation of a luminaire's light distribution in
three directions: B = Backwards, U = Upwards (90° and above),
G = Glare Zone (80° to 90°) Forward.
CORRELATED COLOR TEMPERATURE
Abbreviated CCT, denotes the color temperature of the light
source measured in degrees Kelvin. High CCT, e.g., 6000K, indicates
cold white light, low CCT, e.g., 3000K, indicates warmer light in
the red end of the spectrum.
CUTOFF ANGLE (OF A LUMINAIRE)
The angle, measured up from the nadir, between the vertical
axis and the first line of sight at which the bare source is not visible.
DIRECT LIGHT
Light emitted directly from the lamp or off of the reflector
or reflector diffuser or through the refractor or diffuser lens of
a luminaire.
FLOOD OR SPOT LIGHT
Any light fixture or lamp that incorporates a reflector or
a refractor to concentrate light output into a directed beam in a
particular direction.
FOOTCANDLE
A unit of illuminance. One footcandle is one lumen per square
foot of incident light.
FULLY SHIELDED LIGHTS
Outdoor light fixtures shielded, aimed, mounted or constructed
in such a manner that all light emitted by the fixture, either directly
or from the lamp or a diffusing element or indirectly by reflection
or refraction, is projected below the horizontal plane through the
fixture's lowest light emitting part as certified by a photometric
test report.
GLARE
The sensation produced by the luminances within the visual
field that is sufficiently greater than that to which the eyes are
adapted to cause annoyance, discomfort or loss in visual performance
or visibility. Unlike illuminance, glare does not decrease as viewing
distance from sources increase, only apparent size of the source of
glare decreases with increased viewing distance.
HARDSCAPE
Permanent paving or nonbuilding impervious improvements to
the site, outside of any public street right-of-way, including but
not limited to parking lots, drives, entrances, curbs, ramps, stairs,
steps, medians, loading or storage areas and walkways.
HEIGHT OF LUMINAIRE
The height of a luminaire shall be the vertical distance
from finished grade directly below the center line of the luminaire
to the lowest direct-light-emitting part of the luminaire.
ILLUMINANCE
The quantity of incident light measured in footcandles or
lux.
ILLUMINATION
An alternative term for illuminance. Commonly used in a qualitative
or general sense to designate the act of illuminating or the state
of being illuminated.
INCIDENTAL NONFULL CUTOFF LIGHT
Incidental light which is not full cutoff but which may be
permissible contingent on meeting the requirements of this section
and chapter. Such lighting may include but is not limited to approved
security lighting, building interior lighting or window sign lighting.
INDIRECT LIGHT
Direct light that has been reflected or has scattered off
of other surfaces.
LAMP
The component of a luminaire that produces light. A generic
term for a man-made source of light, i.e., a light bulb.
LIGHT LOSS FACTOR (LLF)
The ratio of illuminance for a given area to the value that
would occur if lamps operated at their initial rated lumen output
and if no system variation or depreciation had occurred.
LIGHT TRESPASS
The shining of light produced by a luminaire beyond the boundaries
of the property on which it is located.
LUMEN
A standard unit of luminous flux. Photometrically, it is
the luminous flux emitted within a unit solid angle (one steradian)
by a point source having a uniform luminous intensity of one candela.
One footcandle is one lumen per square foot. For the purposes of this
Section, the lumen-output values shall be the initial lumen output
ratings of a lamp, as specified by the manufacturer of the lamp.
LUMINAIRE
A complete lighting unit consisting of one or more lamps
together with the fixture, other parts designed to control the light
distribution and other mechanical and electrical components.
LUMINAIRE, CUTOFF
A luminaire whose light distribution at or above an angle
of 90° above nadir does not numerically exceed 25 candela per
1,000 lamp lumens (2.5%), and does not numerically exceed 100 candela
per 1,000 lamp lumens (10%) at or above a vertical angle 80° above
nadir. This applies to all lateral angles around the luminaire.
LUMINAIRE, FULL CUTOFF
A luminaire whose light distribution at or above an angle
of 90° above nadir has zero candela intensity and does not numerically
exceed 100 candela per 1,000 lamp lumens (10%) at or above a vertical
angle 80° above nadir. This applies to all lateral angles around
the luminaire.
LUMINAIRE, FULLY SHIELDED
A luminaire whose light distribution at or above an angle
of 90° above nadir has zero candela intensity but which does not
have a glare-zone restriction.
LUMINANCE
The physical and measurable quantity corresponding to the
brightness of a surface in a specific area from which light is emitted
or reflected (e.g., lamp, luminaire, reflecting material). Can be
measured in candelas per square meter (cd/m2) or footlamberts.
LUX
The standard unit of illuminance. One lux is one lumen per
square meter and the nominal equivalent at 0.1 footcandle.
NIGHTTIME
The hours between the end of evening civil twilight and the
beginning of morning civil twilight. Civil twilight ends in the evening
when the center of the sun's disk is 6° below the horizon and
begins in the morning when the center of the suns disk is 6° below
the horizon.
OUTDOOR LIGHTING
The nighttime illumination of an outside area or object by
any man-made device that produces light by any means regardless of
whether the actual source of the light is outside or within a structure.
OUTDOOR LIGHTING, TEMPORARY
Outdoor lighting that is used for a period of less than seven
days, with at least 180 days passing before being used again or used
annually for a period of 45 days or less.