For the purposes of this chapter, terms used shall be defined as follows:
BOLLARD LIGHT
A short vertical post used in landscaping that contains a lighting
fixture.
DIRECT LIGHT
Light emitted directly from the lamp, off of the reflector or reflector
diffuser, or through the refractor or lens, of a luminaire.
DISABILITY GLARE
The eye's line-of-sight contact with a direct light source,
which causes a momentary blindness.
FIXTURE
The assembly that houses the lamp or lamps and can include all or
some of the following parts: a housing, a mounting bracket or pole socket,
a lamp holder, a ballast, a reflector or mirror, and/or a refractor or lens.
FLOODLIGHT OR SPOTLIGHT
Any light fixture or lamp that incorporates a reflector or a refractor
to concentrate the light output into a directed beam in a particular direction.
FULLY-SHIELDED LIGHTS OF FULL CUT-OFF TYPE FIXTURE
Outdoor light fixtures shielded or constructed so that no light rays
are emitted by the installed fixture at angles above a ninety-degree, horizontal
plane from the base of the fixture as certified by a photometric test report.
Full cutoff fixtures must be installed in a horizontal position as designed,
or the purpose of the design is defeated.
GLARE
Light emitting from a luminaire with an intensity great enough to
reduce a viewer's ability to see, and in extreme cases causing momentary
blindness.
HEIGHT OF LUMINAIRE
The vertical distance from the ground directly below the centerline
of the luminaire to the highest direct-light-emitting part of the luminaire.
LAMP
The component of a luminaire that produces the actual light.
LIGHT TRESPASS
The shining of light produced by a luminaire beyond the boundaries
of the property on which it is located.
LUMEN
A unit of luminous flux. One footcandle is one lumen per square foot.
For the purposes of this chapter, the lumen-output values shall be the initial
lumen output ratings of a lamp.
LUMINAIRE
A complete lighting system, comprised of a lamp or lamps and a fixture.
UNIFORMITY RATIO
The uniformity of light levels across an area, expressed as a ratio
of average to minimum level of illumination for a given area.
The following types of lighting shall be prohibited except when used
on a temporary basis in connection with a special event. In such instances,
they shall be treated as a temporary sign, requiring a temporary sign permit
from the Architectural and Historic Review Board.
A. Laser source light or any similar high intensity light
for outdoor advertising or entertainment.
B. Searchlights such as those used for advertising purposes.
Should any outdoor light fixture or the type of light source therein
be changed after a building or sign permit has been issued, a change request
must be submitted, together with adequate information to assure compliance
with this code, which must be received prior to substitution.
Lighting that does not conform to the antiglare provisions of this chapter, expressed in §
191-4 and §
191-6, concerning the lighting of signs, shall be brought into conformity when a change of use occurs, but no later than five years from the effective date.