Definitions. For purposes of this section, the following terms shall have the following meanings:
BOARD
The Borough of Chatham Zoning Board of Adjustment or Planning Board as appropriate.
FOOTCANDLE (fc)
A unit of illuminance on a surface one foot square in area onto which there is a uniform flux of one lumen.
GLARE
The sensation produced by luminance within the visual field that is sufficiently greater than the luminance to which the eyes are adapted to cause annoyance, discomfort or loss in visual performance and visibility.
HORIZONTAL ILLUMINANCE
The illuminance on a horizontal plane expressed in footcandles (fc).
IESNA
Illuminating Engineering Society of North America, an organization that recommends standards for the lighting industry.
ILLUMINANCE
The area of density of the luminous flux incident at a point on a surface expressed in footcandles (fc).
LIGHT FIXTURE
An electrically powered illuminating device installed outdoors emitting a total light source of more than 1,000 initial lumens per fixture (the equivalent of approximately a single sixty-watt incandescent bulb), including but not limited to devices used to illuminate any site, architectural structure or sign. The term "light fixture" shall include the elements designed to give light output control, such as a reflector or mirror, the refractor or lens, the ballast, the housing, and the attachment of related parts.
LIGHT TRESPASS
Excessive illumination at an adjacent property line that produces light spill and/or glare as measured by the Borough Zoning Official or his/her designee at a point at the adjacent property line at a height of six feet and facing the light fixture(s).
[Amended 3-11-2013 by Ord. No. 13-04]
LUMEN
Measurement of light output. One lumen is equal to the amount of light emitted by one candle that falls on one square foot of surface located one foot away from the candle.
LUMINANCE
The quantity of light reflected or emitted towards an observer, expressed in lumens per square foot.
NADIR
The vertical line projecting downward to the ground from the center of a lens of a light fixture.
RESIDENTIAL
One- and two-family dwelling units.
SHIELDED LIGHT FIXTURE
A light fixture with cutoff optics that allows no direct light emissions above a vertical cutoff angle of 90° above nadir through the light fixture's lowest emitting part. Any structural part of the light fixture providing this cutoff angle must be permanently affixed.
TEMPORARY LIGHT FIXTURE
Any light fixture in place for 30 days or less.
UNIFORMITY RATIO
The ratio of the brightest spot to the dimmest spot, or the ratio of the average brightness to the minimum brightness.
VERTICAL ILLUMINANCE
The illuminance on a vertical plane expressed in footcandles (fc).