The following words, phrases and terms as used in this chapter shall have the following meaning:
A. Artificial Sky Glow. The brightening of the night sky attributable to man made sources of light.
B. Candela. The unit of luminous intensity of a lighting source emitted in a given direction.
C. Curfew. A time each night after which certain electric illumination must be turned off or reduced in intensity.
D. Glare. Light that causes visual discomfort, annoyance or disability, or a loss of visual performance.
E. Landscape Lighting. Luminaires mounted in or at grade (not to exceed 3 feet above grade) and used solely for landscape rather than area lighting, or fully shielded luminaires mounted in trees and used solely for landscape or Facade lighting.
F. Light Trespass. Light flowing across the property boundary. See Figure 16.43.1 for illustration.
G. Lumen. The unit of luminous flux: a measure of the amount of light emitted by a lamp.
H. Luminaire. A complete lighting unit consisting of one or more electric lamps, the lamp holder or holders, reflector, lens, diffuser, ballast, and/or other components and accessories.
I. Luminous Flux. A measure of the total light output from a source, the unit being the lumen.
J. Mounting Height. The vertical distance between the lowest part of the luminaire and the ground surface directly below the luminaire. See Figure 16.43.2 for illustration.
K. Photometric Test Report. A report by an independent testing laboratory or one certified by the National Institute of Standards and Technology (NIST) describing the candela distribution, shielding type, luminance, and other optical characteristics of a specific luminaire.
L. External Point of Service. An outdoor service which a business provides some service to a customer, such as drive up food service, a bank transaction, or the like
M. Shielding. A device or technique for controlling the distribution of light. Four levels of shielding are defined as follows:
1. Fully Shielded. A luminaire emitting no luminous flux above the horizontal plane;
2. Shielded. A luminaire emitting less than 2.0 percent of its luminous flux above the horizontal plane;
3. Partly Shielded. A luminaire emitting less than 10 percent of its luminous flux above the horizontal plane;
4. Unshielded. A luminaire that may emit its flux in any direction.
N. Spill Light. Lighting from a lighting installation that falls outside of the boundaries of the property on which the installation is sited.
O. Temporary Lighting. Lighting installed with temporary wiring and operated for less than 60 days in any calendar year.
Figure 16.43.1: Light Trespass