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Guide Glossary
General service lamp → Incandescent lamp
High-pressure sodium vapour lamp High-pressure → discharge lamps containing sodium vapour. Because Glare the sodium vapour is aggressive Collective term for the reduction at high pressures and would of → visual performance or the destroy glass, the inner discharge impairment of perception due to tube consists of aluminium-oxide high → luminances or luminance ceramic, enclosed in the external contrasts in the visual surroundglass envelope. The → colour of ings. A distinction is made between light produced is in the warm discomfort glare and disability white range. High-pressure sodium glare: the former concerns an vapour lamps require → ignitors objective reduction in vision and and → control gear. the latter a subjective impairment due to any disparity between the → luminance and information Honeycomb anti-dazzle screen content of the observed area. The Anti-dazzle attachment with glare can be caused by the lamp honeycomb structure used to itself (direct glare) or by → reflec- restrict the → light beam and tion of the lamp (reflected glare). reduce → glare. Global illumination In three-dimensional computer graphics, a calculation used to describe the simulation of all ways in which light rays may radiate. Global radiation The sum of solar radiation and surrounding sky radiation. Gobo Common term in spotlight illumination (originally from stage lighting) for a mask or image template (patterned filter) used to create effects and project images using a projecting optical system. Grazing light Type of lighting where the light is incident to the surface at a very shallow angle. Used to emphasise surface structure and texture.
H HDR Abbreviation for → High Dynamic Range High Dynamic Range Describes a very high contrast relationship in a digital image. Images in HDR format can store a higher luminance contrast than Low Dynamic Range with 255 gradations. High-pressure discharge lamps This category includes → mercury vapour lamps, → metal halide lamps and → high-pressure sodium vapour lamps.
Hotel lighting Hotels are public areas with particularly stringent demands on the quality of the lighting design. Hotel lighting includes architecturally-oriented lighting in entrance areas, atmospheric mood lighting in the restaurant areas, multifunctional lighting in conference centres, economical lighting in the thoroughfares and corridors, and private lighting atmospheres in the hotel rooms. Hub Node for connecting network segments or hubs, for example via → Ethernet.
I IES International data format for describing the light intensity distribution of luminaires. Ignitor A component in control gear that facilitates the ignition of → discharge lamps by producing voltage peaks. Incandescent lamp → Thermal radiator where light is created by heating a Tungsten filament. The incandescent filament is enclosed in a glass bulb filled with an inert gas such as nitrogen which prevents it from oxidising and delays the vaporisation of the filament material. Incandescent lamps are available in numerous forms, the main groups being general service lamps with pear-shaped, clear or frosted bulbs, → reflector lamps with a variety of internal reflective coatings and PAR lamps
Edition: 03/01/2010 | Updated version at www.erco.com
made of moulded glass with integral parabolic reflector.
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Individual workplace lighting In contrast to → ambient lighting, this lighting is designed for one specific workplace, e.g. using → task lights.
Key light Type of lighting using → accent light to considerably improve the appearance of an object or setting. To avoid harsh contrast, a → fill light is used.
ILCOS Abbreviation for International Lamp Coding System. It is a uniform → lamp designation system.
KNX Abbreviation for Konnex. Standardised digital system for building control, e.g. for lighting, heating and ventilation.
Illuminance The illuminance, measured in the units of lux (lx), is the ratio between the luminous flux incident upon an area and the size of that area.
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Lambert’s Cosine Law Law which states that the → illuminance is a function of the distance from the light source. Indirect lighting Lighting which is emitted from the The illuminance is inversely proluminaires and indirectly reflected portional to the square of the onto the working plane via reflec- distance. tive surfaces, e.g. → uplights. Infrared radiation Invisible thermal radiation in the wavelength range > 780 nm. Infrared radiation is produced by all light sources, but especially by → thermal radiators, where it constitutes the majority of the emitted radiation. In-ground luminaire → Recessed floor luminaire Interference Physical phenomenon produced when waves that are out of phase are superimposed; it can result in selective weakening of the intensity of various wavelengths. Interference is used in → filters and → reflectors for selective → transmission or → reflection, respectively.
Lamp Electric light source such as an → incandescent lamp, → discharge lamp or → LEDs. In a → luminaire, the light source produces light which can then be directed to the target objects via → reflectors. Lamp cap Component of the → lamp through which the electrical connection to the → lampholder of the → luminaire is made. Lamp cut-off angle With → downlights, this is the angle subtended between the horizontal plane and a straight line extended from the edge of the luminaire to the edge of lamp. It is a dimension for the → visual comfort of a luminaire in addition to the → luminaire cut-off angle.
Interference filter → Filter
Lamp designation system Uniform system for naming electric lamps. The abbreviation Iso-luminance contour diagram of a lamp includes information on the method of light generation, Diagram representing luminance distributions, where a single refer- the bulb material or gas fillings, the wattage and the type of ence plane is shown with conlampholder. tours superimposed of the same luminance. Isolux diagram Diagram representing illuminance distributions, where a single reference plane is shown with contours superimposed.
Lamp life The functional life of a lamp. The functional life of incandescent lamps is based on the failure of 50% of the lamps. The functional life of discharge lamps and LEDs is calculated at the point when the installation’s luminous flux 431