[Added 4-11-2011 by Ord.
No. 2169]
The following words and terms, when used within this chapter,
shall have the following meanings:
ARTIFICIAL LIGHT SOURCE
Shall mean a man-made thing or object from which light originates
(ex: an electrically-powered lamp).
CANDELA (FORMERLY, CANDLE)
Shall mean the "SI" unit of luminous intensity, one candela
describes a luminous intensity of one lumen per steradian.
CUTOFF LUMINAIRE
Shall mean an IESNA classification describing a luminaire
that emits at least 97.5% of its light output below vertical angles
of 90° from nadir at the lowest light-emitting point of its light
source and not more than 10% of its light output above angles greater
than 80° from nadir at the lowest point of its light source.
DEVELOPED PROPERTY
Shall mean real property which has been altered from its
natural state by the lawful addition of improvements such as buildings,
structures, impervious area, etc.
DOWNWARD-AIMED LIGHT FIXTURE
Shall mean a light fixture aimed no higher than 60° above
nadir from the lowest light-emitting point of its light source.
ENERGY
Shall mean the ability to do work.
EXTERNALLY ILLUMINATED SIGN
Shall mean a sign any face of which is illuminated by one
or more artificial light sources located between the reader and the
sign face and directed toward the sign face.
FLOODLIGHT
Shall mean an unshielded artificial light source or lamp
designed to produce relatively uniform illumination across a broad
area.
FULL CUTOFF LUMINAIRE
Shall mean an IESNA classification describing a luminaire
that emits 0% of its light output above angles greater than 90°
from nadir at the lowest light-emitting point of its light source
and not more than 10% of its light output above angles greater than
80° from nadir at the lowest point of its light source.
FULLY SHIELDED LUMINAIRE
Shall mean a luminaire that emits no direct uplight (i.e.,
100% of its light output is below a vertical angle of 90° from
nadir at the lowest light-emitting point of the light source).
GLARE
Shall mean illuminance within the visual field of a human
eye which is sufficiently greater than the intensity of illuminance
to which the eye is adapted that it causes annoyance, discomfort,
reduced vision and/or momentary blindness.
HORIZONTAL ILLUMINANCE
Shall mean the measure, in footcandles, of the total amount
of visible light incident upon (i.e. illuminating) a point within
a horizontal surface taken through the sensor of a light meter held
horizontally upon the point. Within this Ordinance, standards for
"horizontal illuminance" levels shall be interpreted as "horizontal
illuminance measured at ground level" unless specifically stated otherwise.
IESNA
Shall mean abbreviation for "Illuminating Engineering Society
of North America" (also known as "IES") which has a membership consisting
of architects, engineers, designers, educators, students, contractors,
manufacturers, and scientists and which provides technical guidelines,
standards, professional journals, and educational training forums
related to the practice of lighting.
ILLUMINANCE
Shall mean the total amount (density) of visible light incident
upon (i.e. illuminating) a point of a surface from all directions
above the surface measured in footcandles (note: the "surface" may
be a part, or all, of a physical object or an imaginary plane).
INITIAL LIGHT OUTPUT
Shall mean the light output of a lamp, in lumens, after 100
hours of seasoning.
INTERNALLY ILLUMINATED SIGN
Shall mean a sign any face of which is opaque and illuminated
by one or more artificial light sources enclosed entirely within the
sign cabinet and not directly visible from any point outside of the
sign cabinet.
LAMP
Shall mean a radiant light source; the replaceable, electrically-powered
light source of a light fixture.
LIGHT
(see "Visible Light").
LIGHT FIXTURE
Shall mean an electrically powered lighting device consisting
of a lamp, a lamp holder, an electrical ballast (if necessary), and
the means for connecting the device to an electrical power source.
LIGHT SOURCE
Shall mean a thing or object from which light originates
(note: an object that reflects light originating from a different
object is not a light source).
LIGHT SPILLAGE
Shall mean light projected onto a property from an artificial
light source not located upon that property.
LIGHT TRESPASS
Shall mean light spillage not compliant with the requirements
of this chapter.
LIGHTING
Shall mean the celiberate utilization of one or more artificial
light sources to achieve an aesthetic or intended effect.
LUMEN (ABBREVIATED IM)
Shall mean a unit of measurement of luminous flux (i.e.,
of the total amount of light emitted in all directions per unit time)
within the International System of Units.
LUMINAIRE
Shall mean a self-contained lighting system component containing
a light fixture and, as necessary, an outer shell or housing, a mirror
or reflector, an aperture, a lens or refractor and a mounting bracket
or pole socket; within this chapter, the term "luminaire" shall refer
to outdoor lighting luminaires unless otherwise stated.
LUMINOUS FLUX
Shall mean the perceived rate of flow of light from a lamp
or light source; measurements of luminous flux reflect the variability
in sensitivities of the human eye to different wavelengths of light.
LUMINOUS INTENSITY
Shall mean the total luminous flux within a given solid angle,
in units of candelas, or lumens per steradian.
MOUNTING HEIGHT
Shall mean the distance, measured along the nadir, between
the lowest light-emitting point of the light source within a luminaire
or light fixture and the ground surface below.
NADIR
Shall mean the nadir at a particular point is the local vertically
downward direction from that point (i.e., the nadir at a point is
directed from that point along the line of force of the earth's gravity).
OUTDOOR LIGHTING
Shall mean the lighting of areas exterior to the walls of
enclosed buildings and/or within structures having open or partially
open walls such as canopies, porte cocheres, pavilions, gazebos, etc.
POWER
Shall mean the rate at which energy is utilized used by a
device to produce useful work (also called input power or active power);
in lighting, it is the system input power (in watts) for a lamp/ballast
combination.
PROPERTY
Shall mean a tract of land depicted upon the Municipal Tax
Map as one or more lots and which is assessed as a single tax parcel
by the Municipal Tax Assessor.
SEARCHLIGHT
Shall mean aimable light fixture designed for outdoor use
containing an artificial light source having a power rating in excess
of 500 watts and reflectors designed to produce a narrowly conical,
high intensity light beam visible for a relatively long distance but
generally unsuitable for illumination of streets, driveways, parking
fields, pedestrian paths, flags, architectural features, site improvements,
etc.
SHIELDED LIGHT SOURCE
Shall mean a light source which is positioned and/or equipped
with light shielding devices so that it is not directly visible to
any person distant 10 feet or more from the light source, or from
any point upon or outside of the property boundary.
SHIELDING
Shall mean the blocking of an electromagnetic field with
a metallic substance in a manner that reduces electromagnetic waves
radiated; electronic components, wires, lamps, and similar devices
can all be shielded.
SOLID ANGLE
Shall mean a conical volume of space defined by a point (the
vertex of the solid angle), a sphere centered upon the vertex point,
an area segment upon the surface of the sphere and the collection
of rays which begin at the center point of the sphere and which pass
through the points of the perimeter of the area segment upon the surface
of the sphere.
SPOTLIGHT
Shall mean an unshielded artificial light source or lamp
designed to produce a narrow, well-directed beam of light upon a small
area.
STERADIAN (ABBREVIATED S)
Shall mean a unit of measure of a solid angle the value of
which can be determined by placing a sphere so that its center point
is upon the vertex of the solid angle and dividing the area measure
of the surface area segment of the sphere which subtends the angle
by the square of the radius of the sphere (note that this quantity
is not dependent upon the shape of the subtending area segment but
only upon the measure of the segment area).
TEMPORARY LIGHTING
Temporary lighting is outdoor lighting which does not conform
to the provisions of this chapter and which will not be used for longer
than a period of 30 consecutive days; temporary lighting is intended
for uses which, by their nature, are of limited duration such as holiday
decorations, civic events, or construction projects; (note: applications
for Temporary Lighting Permits shall be reviewed and permitted on
a case-by-case basis).
UNIFORMITY
Shall mean a term utilized to describe the variation of illuminance
upon a given plane where variation is expressed as either the numerical
ration of the minimum level of illuminance to the maximum level of
illuminance or the numerical ratio of the minimum level of illuminance
to the average (i.e., arithmetic mean) level of illuminance.
VERTICAL ILLUMINANCE
Shall mean the measure, in footcandles, of the total amount
of visible light incident upon (i.e. illuminating) a point of a vertical
surface taken through the sensor of a light meter held vertically
at the point.
VISIBLE LIGHT
Shall mean electromagnetic radiation which is detectable
by a typical human eye.