Lighting A to Z

GlossaryLight Any radiation capable of causing a visual sensation direct,i.e., visible radiation.Light Output Amount of light produced by a light sourcesuch as a lamp. Measured in lumens or candlepower.Lighting (or illumination) Application of light to ascene, objects, or their surroundings so that they may be seen.Louvre Shield made of translucent or opaque material andpositioned to prevent lamps from being directly visible over agiven angle.Low Pressure Sodium Lamp (LPS) The most efficientman made light source. LPS only produces yellow light thereforeit has a 0 CRI. Example: A SOX lamp.Lumen The unit of measure for the total amount of light froma light source, regardless of direction. Unit lumen, L.Luminaire A fixture or apparatus that distributes, filters, ortransforms the light given by a lamp or lamps which incudes allthe items necessary for fixing and protecting these lamps and forconnecting them to the supply circuit.Luminance (L) In a given direction, the amount of lightcoming off of the surface. Unit candela per square foot, cd/ft 2 .Lux (FC) The metric unit of illuminance. The amount oflumens falling on an area measured in square meters. One lumenfalling on one square meter is equal to one lux.Maximum Beam Candlepower (MBCP) The maximumintensity of the beam in a given direction. Usually in thecenter of the beam. Unit candela, cd.Mercury Vapor Lamp A high-pressure mercury lamp inwhich the light is produced by the mercury vapor and sometimesby a layer of fluorescent material on the inner surface of theouter bulb excited by the ultraviolet radiation of the discharge.Metal Halide Lamp Discharge lamp that produces a whitelight with good color rendering and high efficiency.M.O.L. The maximum overall length of a lamp from the tip ofthe base to the top of the glass.Mortality Rate The number of operating hours elapsedbefore a certain percentage of the lamps fail.50 Product Knowledge