AREA LIGHT: | A luminaire equipped with a lamp that produces over one thousand eight hundred (1,800) lumens. Area lights include, but are not limited to, streetlights, parking lot lights, and yard lights. |
AVERAGE HORIZONTAL FOOT-CANDLE: | The average level of illuminance for a given situation (with snow cover if that is to be expected in the given situation) measured at ground level with the light meter placed parallel to the ground. |
BACK LIGHTING: | An indirect source of light which is located behind the sign surface or is shielded from the viewer’s eyes by a translucent or opaque material. |
CORRELATED COLOR TEMPERATURE (CCT): | The characterization of the color content, or spectrum (“warmness” or “coolness”), of a light source measured in Kelvin (K). Lamps with a CCT of less than 3000K are considered “warm.” Lamps with a CCT greater than 4000K are bluish-white and are considered “cool.” |
DIRECTIONAL FLOODLIGHT: | A fully shielded fixture that is angled no higher than twenty-five degrees (25°) degrees from vertical and which targets a specific area to be lit. |
EXTERIOR LIGHTING: | Temporary or permanent outdoor lighting that is installed, located, or used in such manner to cause light rays to shine outdoors. Luminaires that are indoors that are intended to light something outside are considered exterior lighting for the purpose of this title. |
FLOODLIGHT: | A light fixture that produces up to one thousand eight hundred (1,800) lumens and is designed to flood a well-defined area with light. |
FOOT-CANDLE (fc): | The American unit used to measure the total amount of light cast on a surface (illumination). One (1) foot-candle is equivalent to the illuminance produced by a source of one (1) candle at a distance of one foot (1'). For example, the full moon produces 1.01 fc (fc are measured with a light meter). One (1) foot-candle is approximately equal to one lumen per square foot. |
GLARE: | Stray light striking the eye that may result in: |
A. Nuisance or annoyance glare such as light shining into a window; | |
B. Discomfort glare such as bright light causing squinting of the eyes; | |
C. Disabling glare such as bright light reducing the ability of the eyes to see into shadows; and | |
D. Reduction of visual performance. | |
HOLIDAY LIGHTING: | Exterior lighting consisting of strings or individual lamps, where the output per lamp is not greater than fifteen (15) lumens. |
IESNA: | Illuminating Engineering Society of North America (IES or IESNA). The professional society of lighting engineers. |
IESNA RECOMMENDED PRACTICES: | The current publications of the IESNA setting forth illuminance levels. |
ILLUMINANCE: | The amount of lighting falling on any point of a surface measured in foot-candles, lumens, or lux; foot-candles are measured as lumens per square foot, and lux is measure as lumens per square meter. |
INDIRECT LIGHTING: | A light source that is concealed from public view and separate from the surface and illuminating the sign surface by means of spotlight or similar fixtures. |
LAMP: | The generic term for a source of optical radiation (light), often called a “bulb” or “tube.” Examples include incandescent, fluorescent, high-intensity discharge (HID) lamps, and low-pressure sodium (LPS) lamps, as well as light-emitting diode (LED) modules and arrays. |
LIGHT: | The form of radiant energy acting on the retina of the eye to make sight possible. |
LIGHT POLLUTION: | Any adverse effect of artificial night light including by not limited to, discomfort to the eye or diminished vision due to glare, light trespass, or any manmade light that diminishes the ability to view the night sky. |
LIGHT TRESSPASS: | Light falling on the property of another or the public right-of-way when it is not required to do so. |
LIGHTING: | Any or all parts of a luminaire that function to produce light. |
LUMEN: | The unit used to quantify the amount of light energy produced by a lamp at the lamp. Lumen output of most lamps is listed on the packaging. For example, a sixty (60) watt incandescent lamp produces nine hundred fifty (950) lumens while a fifty-five (55) watt low pressure sodium lamp produces eight thousand (8,000) lumens and a fifteen (15) watt LED bulb produces nine hundred (900) lumens. LED bulbs are eighty percent (80%) more efficient than incandescent lighting. |
LUMINAIRE: | A complete lighting unit, consisting of lamp or lamps together with the parts designated to distribute the light, to position and protect the lamps, and to connect the lamps to the power. When used, includes ballasts and photocells. Commonly referred to as “fixture.” |
LUMINAIRE, PARTIALLY SHIELDED: | The luminaire incorporates a translucent barrier, the “partial shield” around the lamp that allows some light to pass through the barrier of the fixture’s walls while concealing the lamp from the viewer. |
LUMINAIRE, EIGHTY-FIVE DEGREE CUTOFF TYPE: | Luminaires that do not allow light to escape from above an eighty-five degree angle measured from a vertical line from the center of the lamp extended to the ground. |
LUMINAIRES, FULL CUT OFF: | A luminaire designed and mounted level where no light is emitted at or above a horizontal plane running through the lowest point of the luminaire. |
LUMINAIRES, FULLY SHIELDED: | The luminaire incorporates a solid barrier (the shield), which permits no light to escape through the barrier on the top and sides of the fixture. |
LUMINAIRES, UNSHIELDED: | The luminaire only incorporates clear glass, which permits all light to escape. |
NONESSENTIAL LIGHTING: | Lighting that is not necessary for an intended purpose after the purpose has been served. Does not include any lighting used for safety and/or public circulation purposes. |
OPAQUE: | The effect of a part or parts of a luminaire that provide(s) a barrier above and in some cases around the lamp, that does not allow for any light to pass through. |
PANCHANNELED LIGHTING: | Indirect, concealed light source which element is attached directly to the face of the sign. |
SKYGLOW: | The overhead glow from light emitted sideways and upwards. Skyglow is caused by the reflection and scattering of light by dust, water vapor, and other particles suspended in the atmosphere. |
TEMPORARY LIGHTING: | Lighting that is intended to be used for a special event for seven (7) days or less, and temporary construction lighting. |
TRANSLUCENT: | The effect of a part or parts of a luminaire that provide(s) a barrier around the lamp that allows some light to pass through the barrier in a diffused manner, such that the lamp cannot be clearly distinguished. |
UPLIGHTING: | Fully shielded lighting that is directed in such a manner as to shine light rays above the horizontal place. |
WALL WASH: | The diversion of artificial lighting from the exterior surface of a building or structure. (Ord. 543, 9-3-2020) |