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Explanation of terms and parameters

Lm/WLumens/watt. Is the unit used to describe the efficiency of a luminaire or lamp. It describes the total amount of light flowing from a light source per incorporated circuit (watts)Metal core(dt) is a thermally optimised production method of electrical circuit boards. In conjunction with thick copper they allow for higher lateral thermal conductivity. For this, the circuit board material (often plastic reinforced with glass fibre) is replaced with aluminium, which is far more thermally conductive.NAVHigh-pressure sodium lamp. Up to 120 lm/W, but with extremely poor colour reproduction (approx. Ra of 20). Despite a high illuminance value, the light appears to be dark because of the orange colour.power supplyElectrical circuit for conversion of mains alternating voltageOpal glassCryolite glass refers to glass that has a cloudy, milky, matt appearance. Opal glass significantly swirls around the light from light sources and does not allow for defined illumination of given surfaces.OpticsOptics direct the luminous flux from a light source by way of refraction and reflection, and distribute it to the surface to be illuminated. The optics help direct light to where it is required: onto the road, the path etc.ReflectanceThis is the percentage of the luminous flux that is reflected from a surface. A light surface bounces. A dark surface absorbs. A standard concrete road surface is around 27%.Retrofit / LED retrofitis an LED lamp that has a similar size and light distribution to conventional lamps, such as HQL, NAV, etc. Standardised bases enable quick and cost-efficient replacement.RoHSstands for "Restriction of Hazardous Substances". This is a directive restricting the use of certain hazardous substances in electrical and electronic equipment along with the use and placing on the market of hazardous materials in devices and electronic components.Protection classindicates the suitability of electrical equipment, such as luminaires, for different environmental conditions and corrosive stresses (water, moisture etc.), and the level of protection against potential risks for humans when using these luminaires.Protection classis used in electrical engineering for classifying and identifying electrical equipment in terms of existing safety measures for prevention of electric shock. Retrofit lamps require protection class II (= protection insulation). They feature reinforced and double insulation between the mains circuit and the output voltage or metal housing. This safe electrical insulation protects electrically conductive surfaces from contact with other live components.SMDstands for (Surface Mounted Device). These electrical components do not have pins for electrical connection, and are soldered directly onto the circuit board. This makes for a more compact design and less susceptibility to vibrations.Voltage (V)The value that forces the movement of electrons. Comparable with pressure on the water supply. The more pressure the stronger the water jet, the more voltage the more current at the same resistance.Current (I)Unit for the number of electrons flowing through a conductor in a specified time.Alternating currentCurrent where the flow of direction constantly changes. This occurs through quick and repeated alternating of the negative and positive poles at the current source, e.g. a generator

Term Description
Adaption period Time period required by the eyes to become accustomed to the difference in brightness (light / dark).
Bright adaptation, that is, from dark to light, occurs faster. As a result, tunnel entrances and exits are equipped with so-called adaptation stretches.
Amortisation This is the period over which initial expenses are covered by the resulting yield.
Ampere (A) Unit for measuring current
System efficiency factor Electrical efficiency factor of an entire system with multiple individual components. Describes the ratio of input energy and output energy. The higher the system efficiency factor, the higher the efficiency.
Connected load Total power effectively required for operating a device. This power also includes losses, e.g. that arise in power supplies.
Illuminance The unit is lux (lx). 1lx = lm/m2 measure of luminous flux (lm) that a lamp puts out on a defined surface. A candle flame equals 1lx at a distance of 1m (serves as a measure of brightness.)
Binning Process used for classification of different parameters into different groups by way of so-called bins. For white LEDs, binning comprises three areas – forward voltage, light colour and luminous flux. This ensures that only minimal fluctuations occur in a batch of light-emitting diodes
Glare Glare describes an optical or visual fault triggered by excessive brightness, which leads to excessive demands on the visual system. Figuratively, and for purposes of simplification, interference sources that result in overexposure of technical devices are also referred to as glare. A distinction is made between direct glare (extremely bright light, sun) and indirect glare (reflection). Glare can be limited through light control, such as lenses.
CE declaration A CE declaration is required for bringing a product to market within the European Union. To this end, a manufacturer declares that the product fulfils the applicable requirements set out in the relevant Community harmonisation legislation for its affixing, pursuant to EU Directive 765/2008. This is not a seal, but rather an administrative mark that expresses the free movement of correspondingly labelled industrial products in the European internal market. Only where all EU directives applicable for the product are fulfilled may CE marking be effected.
DIP Stands for Dual in-line Package (sometimes also DIL), and refers to a longitudinal housing design for electronic components, which features two rows of pins for push-through installation on opposite sides of the housing. Up until the 1990s this was the classic housing design for integrated circuits. As a result of miniaturisation and the increased number of connections required for integrated circuits, this housing type has since declined sharply.
Energy efficiency For luminaires this refers to total flux (lumens) in relation to the electrical energy used.
ESL Energy-saving lamp, colloquial for compact fluorescent lamp.
EVG Stands for electronic ballast. This is required for use with gas discharge lamps, so as to reduce the discharge current, thereby preventing bursting of the lamp. A ballast is not required for operating light-emitting diodes; the current should however also be regulated for safe operation in this instance too. This task is assumed either by simple resistors or by sometimes elaborate constant current drivers.
Colour reproduction Indicates the level of unadulterated colour reproduction perceived for a surface illuminated with artificial light. The optimal colour reproduction value Ra =100; all colours appear natural.
Direct current Current in which the electrons always flow in the same direction, from the negative pole to the positive pole.
GR The Glare Rating procedure was developed by the International Commission on Illumination, and evaluates glare based on uniform criteria. The lower the value, the lower the (psychological) glare. Applies to workplaces and sports facilities.
HQI Metal halide lamps. Efficiency up to approx. 120 lm/W, excellent colour reproduction.
HQL High-pressure mercury lamp with an efficiency of around 50 lm/W.
ILCOS stands for International Lamp Code System. It competes with the German lamp designation system (Lampenbezeichnungssystem - LBS), which is used primarily in Europe. The aim of the system is to create a comparability and interchangeability of luminaires from different manufacturers.
Heat sinks are mechanical components required for both heat dissipation and cooling. They enable thermal conditions to be created that allow electronic components to be operated within the specified limits, thereby minimising the probability of failure. In retrofits, the circuit board, which is made of aluminium, acts as the heat sink. The heat is transferred to the surrounding air through convection and radiation.
L70 value specifies the time in hours, in which the drop in luminous flux of a luminaire equals 30% under precisely defined ambient conditions. Consequently, the L70 value has little to do with the service life of the product, which consists of substantially more components.
LED stands for Light Emitting Diode. These diodes are tiny electronic chips made of semiconductor crystals. LEDs do not require colour filters: their light is generated directly in a variety of colours by different semiconductor materials.
Power (P) Physical value for amount of energy per unit time. Measured in watts
Circuit board Also known as board/PC board/printed circuit board. The electrical connection of individual components and the connection to external components of an electronic system take place via the circuit board.
Luminance describes the subjective perceived brightness of an illuminated or light-emitting surface. The luminous intensity in a defined section of a surface is measured in cd/m2. (Luminous intensity in specific area).
Light pollution refers to illumination of the night sky through light sources whose light is scattered in the upper layers of the earth's atmosphere. This impacts negatively on flora and fauna. By means of lenses, the light escaping to the top can be redirected in such a way that the entire luminous flux of the luminaire is targeted to the road, square or pavement. Light that was previously lost is utilised and allows lower power LED lamps to be used, while identical or better illuminance of the ground is achieved.
Luminous intensity is measured in candela (cd). Only measures the section of light emitted in a certain direction. Differentiating factors in specific light emissions depending on lamp/luminaire. These determine the distribution of light on the surface to be illuminated. (certain direction).
Luminous flux is measured in lumens (lm) and indicates the total amount of light emitted by a light source in all directions within the visible range.