The ratio of light output of a light source against the electricity consumed. Measured in Candelas per metre square (cd/m2) and represented by the symbol L Technical term for a light fitting or lantern Under BS5489-1:2003 the lowest of these is used in assessing the projectĪn optical controller consisting of a number of blades arranged to obstruct and/or redirect light output from a luminaire The minimum point luminance divided by the average luminance in any row of calculated points between two lighting positions in a street lighting design. It is that light that is spilled in undesired directions, and/or causing undesired effects The proportion of light emitted by the luminaire against that emitted by the light source within the luminaire That part of the electromagnetic spectrum that is visible to humans This can be adapted to provide specific pre-set drive currents which allow controllability of the products light output and wattage Required by LED products to control the electrical supply to banks of LEDs. The generic term for a traditional light source It is important to keep the junction temperature as low as possible in order to gain the expected longevity stated for the product Is the temperature measured at the point where an LED creates the emitted light. Measured in lux and represented by the symbol EĪ diagram showing the light distribution on a surface by means of contour type lines where each contour joins points of like illuminance The measure of light arriving at a given point. Is a two digit number that defines the relative ingress protection of a product. It allows more accurate data to be collected from products which utilise LED as their light source Testing equipment which measures various aspects of light output including total luminous flux, colour temperature and colour rendering index. That light emitted by a luminaire that has an adverse effect on a given visual task For further information on G4, G5 and G6 glare ratings see EN 13201 The preferred connector between a pendant luminaire and its bracket that resolves all the problems associated with the more dated screw type connectorsĮxpression for luminaires where there is an absolute cut off of light above the horizontal. Light that makes a given visual task uncomfortable Light that adversely affects one’s ability to undertake a given visual task Lighting where the target area is lit directly from the luminaire rather than via another surface Luminaire where the connection between it and the column is via an offset spigot Translucent or frosted glazing that engenders a more even light distribution Lighting that emanates in many directions with no peak intensity in any given direction Many CMS systems use DALI interface to communicate with street lighting equipmentĪward winning adjustable reflector system that tailors light distribution to the area to be lit. Stands for Digital Addressable Lighting Interface and is a standardised communication protocol used with electronic control gear such as LED Drivers. The subjective appearance of different levels of lighting within the visual field The numeric expression of colour appearance, expressed in Kelvin The relative ability of a light source to enable the identification of colour The relative perception of warmth of light, warm, intermediate or cool. The angle over which the intensity from a reflector drops to half of the peak valueĪ measure of luminous intensity from a lamp daytime or night timeĪ reflector that distributes light differentially in specific directionsĪ shield type of apparatus to prevent light spill from a luminaire The process whereby eyesight adjusts to relative levels of brightness, e.g.
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