Advertising Display.Means advertising structures and signs used for outdoor advertising purposes; not including on-premises (exterior portable or interior) advertising signs.
Ambient Light.The general overall level of lighting in an area from lighting not subject to this chapter.
Brightness.Strength of the sensation that results from viewing surfaces from which the light comes to the eye.
Candela (cd).Unit of luminous intensity. One candela is one lumen per steradian. Formerly called the candle.
City Engineer.The city engineer of the city of Palm Desert or a representative(s) designated by the city engineer of the city of Palm Desert.
Contrast.The difference between the luminaire luminous brightness and the brightness of the surrounding area.
Decorative Lighting.Lighting products used for decorative effects versus lighting performance. Examples of decorative lighting include, but are not limited to, fountain lighting, lighting fixtures (pole, post or bollard style) creating a visual effect with low lumen output, led commercial outdoor string lighting, building wall sconce and chandelier lighting with low lumen lamp sources.
Director.The director of community development for the city of Palm Desert or a representative(s) designated by the director of the city of Palm Desert.
Disability Glare.Glare resulting in reduced visual performance and visibility. It is often accompanied by discomfort.
Discomfort Glare.Glare that produces discomfort, but does not necessarily diminish visual performance.
Fixture.The assembly that holds the lamp in a lighting system. It includes the elements designed to give light output control, such as a reflector (mirror) or refractor (lens), the ballast, housing, and the attachment parts.
Foot-candle.One foot-candle is one lumen per square foot. This simply means the amount of light which hits one square foot.
Full-Cutoff.Outdoor light fixtures shielded or constructed so that all of the light rays emitted by the fixture are projected below a horizontal plane passing through the lowest point on the fixture from which light is emitted. Drop or sag lensed type fixtures are not allowed. IESNA classification that describes a luminaire having a light distribution in which zero candela intensity (visible light) occurs at or above an angle of ninety degrees above nadir. Additionally, the candela per one thousand lamp lumens does not numerically exceed one hundred (ten percent) at or above a vertical angle of eighty degrees above nadir. This applies to all lateral angles around the luminaire.
General Outdoor Lighting.All outdoor lighting used for, but not limited to, walkways, parking lots, equipment yards, outdoor security, outdoor retail or restaurant areas, automotive dealers (display areas only), assembly or repair areas, recreational facilities and similar applications where the use of the space or area requires accurate color rendition and light for ease of movement.
Glare.The lighting from a single or multiple lighting fixtures that causes one of the following conditions:
1. Produces sufficiently greater luminance (light) in an area to which the eyes are adapted to. This is known as discomfort glare.
Produces sufficiently greater luminance (light) in an area which causes visual performance loss and visibility. This is known as disability glare.
High Intensity Discharge (HID) Lamp.In a discharge lamp, the emitted energy (light) is produced by the passage of an electric current through a gas. High-intensity discharge includes mercury, metal halide, and high pressure sodium lamps. Other discharge lamps are LPS and fluorescent. Some such lamps have internal coatings to convert some of the ultraviolet energy emitted by the gas discharge into visual output.
High-Pressure Sodium (HPS) Lamp.A gas-discharge lamp that uses sodium in an excited state to produce light. There are two varieties of such lamps: low pressure and high pressure. Low-pressure sodium lamps are the most efficient electrical light sources, but their yellow light restricts applications to outdoor lighting such as street lamps. High-pressure sodium lamps have a broader spectrum of light than the low pressure, but still poorer color rendering than other types of lamps. Low pressure sodium lamps only give monochromatic yellow light and so inhibit color vision at night.
IESNA.Illuminating Engineering Society of North America.
Incandescent Lamp.Light is produced by a filament heated to a high temperature by electric current. These lamps include MR lamps, tungsten halogen lamps, PAR and R lamps. EISA 2007 set new performance requirements for certain common light bulbs, requiring that these bulbs become approximately twenty-five to thirty percent more efficient than the light bulbs by 2012-2014. Overall, the intent of this is to bring into the market more efficient light bulbs. Some new incandescent products could be introduced by the effective dates of the law, including a bulb by General Electric that will decrease the amount of energy required. Non-incandescent bulbs, such as compact fluorescent (CFL) and light emitting diodes (LED) already meet the Tier I standards introduced.
Induction Lighting.The internal electrode less lamp or induction light is a gas discharge lamp in which the power required to generate light is transferred from outside the lamp envelope to the gas inside via an electric or magnetic field, in contrast with a typical gas discharge lamp that uses internal electrodes connected to the power supply by conductors that pass through the lamp envelope.
Installed.Any legal installation of outdoor light fixtures after the effective date of the ordinance codified in this chapter.
Light Emitting Diode (LED) Source.An electronic semiconductor device that emits light when an electric current passes through it. They are considerably more efficient than traditional light bulbs and provide for long lamp life. LEDs are used in many applications such as flat-screen video displays, indoor and exterior lighting fixtures.
Light Pollution.An unwanted effect of manmade outdoor lighting that contributes to the effects of sky glow, light trespass, and/or glare.
Light Trespass.An undesirable condition in which exterior light is cast where it is not wanted.
Lumen.A unit measurement of a light bulb, arc tube or light emitting diodes (LED) light output expressed as initial lumens or lumen output.
Luminaire.A complete lighting unit consisting of a lamp or lamps and the parts designed to distribute the light, to position and protect the lamp(s), and to connect the lamp(s) to the power supply. (Also referred to as fixture.) The complete lighting unit, including the lamp, the fixture, and other parts.
Mercury Lamp.The mercury vapor lamp is a high intensity discharge lamp. It uses an arc through vaporized mercury in a high pressure tube to create very bright light directly from its own arc. Mercury lamps are not approved in the city of Palm Desert.
Metal-Halide Lamp.This type of lamp is also known as an MH lamp. It is an HID lamp (high intensity discharge), which means it provides most of its light from the electric arc within a small discharge tube. It is becoming increasingly popular due to its good quality white light and good efficiency. The most prominent use of the MH lamp is in stadiums and sports fields. It is also used widely for parking lots and street lighting in urban areas.
Mounting Height.The distance from the finished grade to the top of the lighting fixtures including any lighting fixture foundation.
Municipal.An area, street or facility which is owned or managed by the city of Palm Desert or is associated with a city of Palm Desert facility such as parks, recreation facilities or a city-owned or managed building such as City Hall.
New Development Area.Any development in previously unimproved areas. This includes new developments generally recognized as planned housing, industrial or commercial developments.
Non-Cutoff.A luminaire having a light distribution in which no limitation of light intensity occurs above ninety degrees above nadir.
Off-Street Lighting.Lighting for off-street parking in public, private, municipal or restricted parking areas. All lighting positioned off the street in public and private properties, i.e., parking lots, building lighting, walkway lighting, parks, and fenced yards.
Outdoor Light Fixture.Any lighting product intended and designed for outdoor use to provide illumination of a defined area or subject.
Parking Area.An area, other than a public street, designed or used primarily for parking.
Pedestrian Scale.A luminaire mounted at no more than ten feet above finished grade and intended to illuminate a walking path or small pedestrian area.
Photometry or Photometric.The quantitative measurement of light level and distribution. This information is developed with programs designed to illustrate foot-candles numerically on a project site plan.
Plasma Lighting (LEP).Plasma lamps are a type of gas discharge lamp energized by radio frequency (RF) power which produce high illuminance for exterior applications such as streets, large big box parking lots and sports lighting applications. The LEP lamps have a life ranging from thirty thousand to fifty thousand hours, a CRI of 95. Their LEP lamp is able to operate up to fifty percent more efficiently than conventional HID (high-intensity discharge lamp) lamps while generating the same maintained lumens as a conventional four hundred watt system at about half the energy. The technology also allows the lamp to be dimmed to fifty percent of the rated lamp lumen output.
Recreational Facilities.Public, municipal or private facilities designed and equipped for the conduct of sports, leisure time activities, and other customary and usual recreational activities. Outdoor recreational facilities include, but are not limited to, fields or stadiums for softball, baseball, football, soccer, golf courses, driving ranges and other "field sports," and courts for tennis, basketball, volleyball, handball and other "court sports."
Reflector.Controlling light output by means of reflection (mirror).
Refractor.Controlling light output by means of refraction (lens).
Semi-Cutoff.Outdoor light fixtures designed or constructed so that ninety-five percent of the light rays emitted by the fixture are projected below the horizontal plane passing through the photometric center of the fixture from which the light is emitted. A luminaire light distribution in which the candela per one thousand lamp lumens does not numerically exceed fifty (five percent) at or above an angle of ninety degrees above nadir, and two hundred (twenty percent) at or above a vertical angle of eighty degrees above nadir. This applies to all lateral angles around the luminaire.
Sky Glow or Urban Sky Glow.Any adverse effect of manmade light that produces direct lighting into the sky from the lamp compartment that is not shielded.
(Ord. 1272 § 1, 2014)
