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Lighting Terminology

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3rd Edition

Lighting Terminology | 32 | Lighting Terminology

Lighting Design GuideDesigning a basic lighting scheme requires the consideration of many factors, not just the achievement of a desired lighting level. Basic objectives must first be established, such as:zz What sort of tasks will be performed in the area?zz What ‘mood’ needs to be created?zz What type of lighting will create a comfortable

environment?zz What is interior designer vision?

There are also standards and legislation that need to be complied with. For example:zz How energy efficient must the lighting be?zz How will Building Regulations affect the design?zz Is emergency lighting required?

When all of these objectives and requirements have been established, they can be expressed as a series of lighting criteria in order to facilitate a quality lighting design. Criteria that would normally be considered are:

1. Level of IlluminationThe perception of space is affected by the nature of the light through which it is seen and the nature of the surfaces off of which the light is reflected. The primary purpose of an artificial lighting system is to provide sufficient illumination for the performance of visual tasks. The greater the degree of difficulty of the task, the higher the required illumination levels. Adequate lighting should be provided in all public rooms, walkways, parking areas, reception areas, signs, exhibits, service areas and paths.

2. Uniformity & Ratios of IlluminanceThe combination of luminaires selected should evenly illuminate the working plane and appropriately illuminate walls and ceiling in relation to the task illumination, so that a pleasant and comfortable environment is achieved. In specific areas, increased directional lighting may be required to create a defined or more intimate environment.

3. GlareThe acceptable level of glare should be established as appropriate for the application

4. Colour & Room ReflectanceThe colour appearance of the lamps should be natural for the application and complement the interior colour scheme, which should be chosen with an appreciation of the reflectance values that will be achieved. Lamps should be selected with appropriate colour rendition properties, for colour discrimination and reduction of eye fatigue.

5. Energy EfficiencyLuminaires should be selected to meet the requirements of the Building Regulations. The distribution characteristics should also match the requirements of the criteria above.There are seven classifications of energy as follows:A1, A2, A3, B1, B2, C, DThe A1 classification is the most efficient. “A” classifications are only achieved with electronic ballasts, with B2, C & D classifications covering most magnetic ballasts. Classification B1 is in the crossover region between some types of electronic, and low loss magnetic ballasts.A single 36 Watt fluorescent fitting with a B2 ballast will have a total input power of around 43 Watts. The same luminaire with a B1 ballast would have a total input power of around 41 Watts

6. Special ConsiderationsCertain applications require additional considerations, such as the addition of display lighting, the arduous nature of the environment or the use of Display Screen Equipment. Luminaires should be selected and the design completed with these elements in mind, where appropriate.After these criteria have all been considered, a lighting scheme calculation can be undertaken. The most popular method of establishing the quantity of luminaires required, the illumination level achieved and the luminaire layout, is to use computer software created specifically for lighting design. It is important to remember that all the criteria above must still be considered prior to using computer software, if a satisfactory scheme is to be produced.

Lighting TermsDaylightNatural light from the sky, usually split into two components; direct light from the sun, and diffuse daylight from clouds or blue sky. Sometimes a «circumsolar» component of bright sky near the sun is considered in very accurate daylighting analyses.

Contrast (colour contrast)The degree to which two colours differ from one another. Saturated colours tend to produce higher contrast than pale colour. Colour contrast is useful because it provides visual

interest without causing visual fatigue. Strong colours can be produced by preferential lighting of coloured surfaces, but coloured luminaires (or lamps) combined with coloured surfaces produce particularly saturated colours and rich contrasts .

Brightness Subjective experience of the brightness of an object or surface , as opposed to the objective measurement of luminance with a meter. Brightness is determined by the measured luminance of the object and the adaption level of the viewer. Since adaptation level cannot be measured, neither can brightness.

Adaption The mechanisms by which the human eye changes its sensitivity to light, in order to optimize vision over a wide rang of brightness.

Reflectance The reflectance of all surfaces varies with the azimuth and elevation angle of incident light, its polarity and its spectral composition (colour), as well as with temperature, humidity etc . Therefore the complete reflectance characteristic of a real surface is far too complex to measure. Surface are usually approximate according to their reflectance under perfectly unidirectional white light (diffuse reflectance), and under mono directional white light (specular reflectance). Diffuse reflectance values are usually used in light calculations, but specular reflectance are useful for calculating reflections of luminaries in computer screens.

Retina An extension of the brain which forms a photoreceptive surface at the back of the eye. The term retina is derived from the Latin word for a net, which is what the dissected retina looks like. The retina contains photoreceptive rod and cone cells, as well as cells which modify this visual information before it is passed to the visual cortex of the brain. The retina plays a crucial role in creating and filtering visual information which may be useful in making decisions or responding physiologically to our environment

Cone cellA light-sensitive cell, cone cells are concentrated in the centre (fovea) of the retina. Cone cells are less sensitive than rod cells, but give colour vision and are the main source of visual sensation in normal (photopic) conditions.

Rod cellA light sensitive cell, rod cells are found on the periphery of the retina. Rod cells are more sensitive than cone cells, but give only monochromatic vision. They become the main source of visual sensation in low- light (mesopic and scotopic) condition.

Accommodation The ability of the lens of the eye to change its focal length, to focus on nearer or more distant objects. Accommodation can be lost after several hours focusing on a close visual task such as a drawing or computer screen. Health and safety regulation stipulate that workers should be provided with long views to allow their eyes to «defocus» on distant object, to maintain accommodation. For this reason, workstation should never face walls, and distant features within the space should be well illuminated to allow longer views.

The table below is a guidance for recommended light level in different spaces:

IES Standards illumination level

General building Areas

Circulation Area100 Corridors, passageway150 Lift150 Stairs150 Escalator30 External covered ways

Entrances

150 Entrance halls, lobbies, waiting rooms

500 Enquiry desk300 Gate houses

Kitchens150 Foods Stores500 General

Outdoor

150 Controlled entrance halls or exit gate

30 Entrance and exit car park30 Stores, Stockyards50 Industrial covered ways

Staff Restaurants

300 Centre Cafeterias, dinning room

Medical and first aids centres

500 Consultant room, treatment areas

100 Medical Stores150 Rest rooms

Staff room

150 Changing locker and Cleaner’s room, cloakrooms lavatories

150 Rest roomsStore and stock rooms

300 Telecommunication board, switch board rooms

Garages

30 Parking areas(interior) general repairs servicing

50 External apron generalLaboratories

750 GeneralLaundries & dry cleaning works

300 Receiving, storing, washing ,drying, ironing, cleaning

Printing machine room500 Presses

Graphic reproduction

IES Standards illumination level

General building Areas

500 GeneralOffice

500 General &typing office750 Deep plan general offices750 Conference rooms500 Executive office500 Computer rooms750 Drawing offices300 Print room

Shops500 Conventional with counters500 Conventional with display500 Supermarkets

Public and educational building assembly and concrete halls

100 Theatre and concert halls50 Cinemas

500 Multipurpose

500 Examination halls, seminar rooms, teaching spaces

Libraries150 Shelves, book stack300 Reading table

300Reading rooms, newspaper

and magazines

100 Closed book storeMuseum and Art galleries

300 Exhibits insensitive to light150 Light sensitive exhibits50 Specially light sensitive ehhibit

Hospital50-30 Ward unit bed heads general150 General0.1 Night500 Pharmacies dispensing bench150 Shelves300 Reception general500 Enquiry desk

400 Operating theatre suits general

50-30 Operating area

500X-ray department radio diagnostic and rooms

fluoroscopy500 Dental surgeries

Lighting Terminology | 54 | Lighting Terminology

Uniformity The difference (expressed as a fraction) between the minimum and average illumination values for a specified work plane. Very poor uniformity can lead to noticeable differences in illumination, but in most cases the purpose of a uniformity specification is to ensure a minimum illumination value for a work area, so that workers do not suffer eyestrain. For instance if the average illuminance is 400 lux with a uniformity of 0.7, the minimum value should be 400x0.7 uniformity in the immediate task area, and 0.5 over the surrounding area.

Shading The revelation by the slow or sudden variations in laminated object. Areas of the object where the surface is inclined relative to the prevailing light direction , will be of lower luminance, because of the cosine rule. Moderate or strong shading is essential for manual industrial tasks and for museum exhibits. It is achieved by strongly directional light, often from local task lighting, or from downlights. “Norhlight” saw-toothed roofs in factories produce strong shading from daylight by shutting out light from one direction. Shadows disrupt outlines and make objects less recognizable.

Shadowing The casting of shadows by an object, which result in poor visual conditions in the shadowed area. An example would be the shadowing of an industrial workbench by an overhead machine or gantry placed close to a luminaire. Cast shadows not only reduce illumination levels, but also disrupt the outline of viewed objects placed within the shadow. Shadowing can also cause unplanned and unsightly dark lines on architectural features, for instance in an atrium. Shadowing should be avoided by the careful placement of luminaires relative to architectural features or machines.

Diffuse Light which is scattered in all directions by a transmissive or reflective process. A “diffusing” panel in a luminaire scatters light which is transmitted through it, while a matt white louver scatters light which is reflected from it. Diffuse is the opposite of specular. Shadows can also be described as diffuse when they are created by a diffuse source or by uplighting, and are therefore soft-edged and gradual

Lighting MeasurementsThe main units of measurement for light are the Lumen and Lux.

1. Lumen“Symbol:m”This is a measurement of the light output from a lamp.Lumen Outputs of Different Lamp Types:

Lumen Type Typical Lumen Output

GLS 100 Watt 1300

12V 50 Watt dichroic TH 950

Fluorescent: 18 Watt 1150

58 Watt 4600

Compact fluorescent : 18 watt 1250

Tungsten Halogen : 100 watt 1800

Lumen Type Typical Lumen Output

Mercury Vapour: 250 Watt 13700

Mercury Vapour: 400 Watt 24000

Metal Halide: 250 Watt 20500

Metal Halide: 400 Watt 38000

High Pressure Sodium: 250 Watt

27500

High Pressure Sodium: 400 Watt

47500

Low pressure sodium : 55 watt 8000

LED : 210 watt 12300

2. Lux“Symbol:E”This is a measurement of the light intensity falling on a surface. One lux is equal to one lumen per square metre. In order to calculate the lux level on a surface we need to consider the following:

1. Room dimensions2. Luminaire mounting height3. Height of the work plane (desk, workbench or floor)4. Reflectances of the ceiling, walls and floor5. How dirty will the room surfaces and the luminaire

become in several years time6. Photometric data on the fitting to be used7. Initial lumen output of each lamp x the number of

lamps8. What will the lamp lumen output be in several years

timeThese parameters are usually processed in a computer program “Dialux” which will tell us how many fittings are required for the space. The result will be the “maintenance illuminance” which tells us that the light level will be in Lux after several years of operation. This means that if we measure the illuminance of a new installation the Lux level should be considerably higher than the Lux we designed for.

3. Candela:“symbolcd”SI unit of luminous intensity, 1 candela = 1 lumen per steradian.

Intensity A measure of the total amount of light leaving a source in a given direction. Defined as the number of lumens per steradian, and measured in candela (cd).

Contrast(Luminance or Brightness contrast) A measure of the difference in luminance between an object and its background.

Defined

C=L

obj - L

b

Lb

Where:Lobj is the luminance of the object, Lb is the luminance of the backgroundThis measurement of contrast is only useful in the laboratory, because in real situations objects seldom have sharply-defined luminance boundaries. A more useful measurement would be

Anisotropic The subtly varying appearance of a surface, dependant a high degree of visual interest.

Direct lightLight which travels directly from the source to the target surface without reflection. Direct luminaiers can produce strong shadowing and highly directional light with poor modeling.

Direct/indirect lightingLighting which combines the efficiency of direct light with the visual comfort benefits of indirect light. This can be achieved with a single pendant luminaire, or by a combination of down lights with wall washers or uplights.

Balanced light A luminaire or light installation in which the ratio of direct to indirect light can be varied via a control system. Can be achieved by a suspended direct to indirect light can be varied via a control system. Can be achieved by a suspended direct/indirect luminaire with separate upwards and downward lamps,or by separate down lights and wall washers/up lights.

Illumination The process of lighting an object.

Illuminance: “symbol E”(unit : lux) (lumen per square m)

Glare ControlBattens and recessed fittings with flat panel diffusers emit light over a wide angle. This is good for general lighting but becomes a problem in offices where computer screens are used. Light sources of these types will reflect in the computer screens and create glare which makes the screen harder to work with. This problem is worse on older computer systems that use a predominately dark screen.The solution is to control the angle at which the light is able to leave the luminaire. If we can keep the light angled mainly downwards with reduced output at angles above 55 degrees the problem will be greatly reduced. Such fittings are called low brightness luminaires. A room full of low brightness fittings will appear rather dark as there is very little vertical illuminance (on the walls) because most of the light is going downwards.

Glare Rating SystemsIn order to achieve comfortable glare free conditions in the workplace it is necessary to control the luminance (brightness) emitted from a luminaire at certain angles. This is especially important in situations where computer monitor screens are being used.One glare rating system used overseas is the British CIBSE (Chartered Institute of Building Services Engineers) standard LG3. This system uses three categories of performance rating for luminaires used in computer monitor areas of the workplace. It sets two maximum luminance limits over a range of angles specified in the standard.The average luminance is an average over the entire area of the luminous element. This parameter is calculated.The patch luminance is a measurement of any 25mm diameter area on the luminous element. This parameter is measured.

The luminance limits for each of these parameters vary according to the type of computer screen (negative or positive image) and on whether the screen has an anti reflective system.In Australia a glare index system is used which takes into account the actual installation parameters as well as the luminaire. This system is a relative measurement of the visual discomfort of a seated observer who is looking straight ahead. It is calculated in a computer program (from Lighting Analysts) which divides the given room area into 100 sections and places the observer in each of those positions. The program then effectively rotates the observer through 360 degrees and calculates the glare at each angle for each of the 100 positions. The program prints the worst case figure only.Room reflectances have a major part in this calculation. If the floor or walls are too dark the background luminance will be reduced due to there being less inter reflected light. As the glare calculation involves background luminance, a brighter background will give lower glare figures.

Disability glare Light which reduces the visibility of a work task. Any light incident on the eye is slightly scattered by the cornea, and produces a “veiling luminance “ over the entire visual field. When the task is comparatively dark, and other areas of the visual field (such as windows) comparatively bright.

Active lighting “The meaning change of light”. The continous variation of lighting conditions in the workplace via a lighting control system, either to reduce visual monotony in poorly-day lit interiors, or to create visual interest in feature areas. Active lighting may be controlled by a time clock according to a preset cycle, or may be daylight-linked. The colour, direction, and intensity of the light may be varied, active lighting is not dependent upon a particular luminaire, but self-luminous luminaires are often most effective.

Darklight A specular mirror reflector in a down-lighter that appears dark when viewed across the ceiling, even when the lamp is turned on. Dark lighters are usually specified because of their high utilization factor, but the unshielded lamps can cause distraction and disturbance, and the mirror reflectors should not be used in conjunction with uplight. They also produce strong shadowing and highly directional light with poor modeling darklights can produce unsightly “scallops” of light on walls and other vertical surfaces.

Self-luminousA luminaire which appears lit when viewed from any direction. As opposed to a darklight which does not appear lit when views across a ceiling. Self-luminous luminaires give softer shadowing and better modeling than darklights, and give brighter and more even illumination of walls and other vertical surface.

Scallop The character curved pool of light thrown onto a wall by a ceiling luminaire placed near the edge of the ceiling. Scallops may be unplanned and unsightly, such as those resulting from poor placement of downlight, or they may form intentional and attractive patterns.

Lighting Terminology | 76 | Lighting Terminology

the rate of change of luminance per meter (or per steradian) –but unfortunately this is difficult both to measure and to predict.

Colour temperatureThe colour qualities of a lamp are characterized by two different aspects - colour temperature and colour rendering.

Incandescent (240V) 2800 degree K 100

Incandescent 12V Dichroic 3000 to 4000 degree K 100

Warm White Fluorescent

3300 degree K and below 50 to 90

Cool White Fluorescent

3500 to 4000 degree K 60 to 90

Daylight Fluorescent (Cold

White)6000 degree K

and above 80 to 90

Compact Fluorescent

2740 to 4100 degree K 86-92

Linear fluorescent 3000 to 6500 degree K 53-92

Quartz Metal Halide 4200 degree K 85

Ceramic Metal Halide 5400 degree K 96

Halogen 2800 degree K 100

High pressure sodium

1900 to 2000 degree K 20-22

Low voltage 2925 to 3200 degree K 100

The colour rendering of fluorescent lamps in the table above varies from different manufacturers.

Hot Warm

Cold

Application of Different Colour Temperature Lamps

1. Use warm white for accentuating warm colours (red, brown cream etc.)

2. Use cool white with cool colours like grey and blue3. Use daylight colours in hot climates as a warm lamp

makes people feel hotter

Colour renderingIs the ability of a lamp to give good colour representation of the object it is illuminating. The unit of measurement is Ra.Some lamps have better colour rendering than others and should be selected for colour critical applications.

Ra Application

Above 90 Colour Matching, Picture Galleries

80 - 90 Homes, Restaurants, Textile Industry

60 - 80 Offices, Schools, Light Industry

40 - 60 Heavy Industry

20 - 40 Outdoor

BallastsA ballast is a coil of copper wire wound around a laminated iron former. A coil wound in this way has an electrical property called inductance. An inductance creates a resistance to the flow of alternating current and is used in a fluorescent fitting to control the current flowing through the lamp. Therefore each lamp must be operated with the appropriate ballast.

DimmerAn electric or electronic device that can reduce a fixture’s brightness, usually with some loss of color temperature. Optical dimming mechanisms maintain color temperature

DMXIn short, it’s a system of controlling “intelligent” lighting fixtures and dimmers.Technically, DMX is an abbreviation for DMX512-A, the ESTA (Entertainment Services Technology Association) Standard for controlling lighting equipment and related accessories.A wide variety of lighting control consoles, controllers and other devices that output DMX signals can be used to connect to an even greater variety of lighting fixtures and accessories that can be controlled by DMX. DMX controlled lighting systems are used in many professional settings, including concert lighting, stage lighting, studio lighting, theme park attractions, and much more.In recent years, the DMX standard is being used more frequently in Architectural lighting projects, including illumination of building exteriors, accent lighting, general purpose building management and high-end residential lighting. This is due primarily to the high popularity of LED based lighting fixtures, which are frequently controlled via DMX signals.

DALIDALI stands for Digital Addressable Lighting Interface. It is an International Standard (IEC 62386) lighting control system providing a single interface for all Electronic Control Gears (light sources) and Electronic Control Devices (lighting controllers).The DALI Standard enables dimmable ballasts, transformers, relay modules, emergency fittings and controllers from different manufacturers to be mixed and matched into a single control system. A DALI system provides designers, installers, building owners, facility managers and end-users a powerful and flexible digital lighting system with security of supply from many sources.Simply, DALI (digital addressable lighting interface) is a two-way communication system that brings digital technology to lighting. An international standard for communication, DALI defines the commands that ballasts need to recognize in order to be considered DALI ballasts. The system allows individual ballasts to “talk” to the user ... and allows the user to “talk” back via DALI controllers, computers equipped with appropriate software, or building management systems (BMS).

WhatisaDALILine?A DALI Line is a network of up to 64 DALI light sources (ballasts, transformers, emergency fittings etc.), addressed from 0 to 63. DALI ballasts are controlled by commands that can be sent to individual ballasts, to groups of ballasts or broadcast to all ballasts on the line.A DALI ballast is an intelligent device that can be configured to remember its power-on level, maximum level, minimum level, system failure level, fade rate and fade time. A ballast can belong to up to 16 groups and store up to 16 preset scene levels.A true DALI lighting system can report the level of every ballast and the status of every ballast and lamp. It can automatically test emergency fittings and report their status. True DALI systems also enable controllers from multiple vendors to be used on the DALI Line.

WhatarethecomponentsofaDALILine?A DALI Line consists of the following components:zz One or more DALI Power Supplies

to a maximum current of 250mA.zz From one to sixty-four DALI

ECGs(electronic control gears) ie. ballasts, transformers, inverters, relay modules, EXIT signs etc.

zz One or more DALI ECDs (electronic control devices) ie. Line controller, group controller, sensor, switchplate etc.

WhatisaDALIControlSystem?DALI Control lighting systems can be scaled from single rooms to complete buildings and campuses.A simple system could consist of a few light fittings and a switch connected to a DALI group controller. The switch provides on/off control and up/down dimming of the fittings. Minimal configuration is required and ballasts do not need to be individually addressed.A grouped system consists of multiple ballasts individually addressed on a DALI Line. Addressing of the ballasts takes approximately 15 minutes for random addressing and 30 minutes for sequential addressing. Inputs on a Line Controller or a group controller can be configured to provide switching and dimming as required. The functionality of the inputs depend on the controller’s

Lighting Terminology | 98 | Lighting Terminology

capabilities however typical examples include switches, pushbuttons, occupancy sensors and light level sensors. Multiple DALI Lines can be linked together with DALI gateways or controllers that combine DALI Lines onto an Ethernet backbone. Gateways require a centralized server to provide time scheduling while the more powerful controllers provide localized scheduling and control options in addition to the gateway functions.

WhataretheadvantagesofDALI?For lighting designers and consultantszz Distributed intelligence for flexible and reliable controlzz Control of individual lights, groups and DALI Lineszz Easy configuration & reconfiguration for changing

circumstanceszz Simple interface with building management systemszz Logarithmic dimming behaviour matching the human eyezz Increased energy savingszz Options for emergency lighting

For installers and electrical contractorszz Simple 5-core wiring, no special control cable, no polarity,

no termination and no segregation requiredzz Easy base-building commissioningzz Easy commissioning for tenancieszz Building lighting and emergency lighting on the one

systemzz No need to switch the mains voltage (handled internally

by the ballasts)For facilities managers & maintenance contractorszz Status reporting of lamps and ballastszz Simple modification - no need to rewire for changing

tenancieszz Lower maintenance costszz Increased energy savings due to dimming and control

capabilitiesFor building occupants & tenantszz Customized lighting preferenceszz More comfortable lightingzz Individual controlzz Easy modification

Maintenance Factor (MF)The maintenance factor is a value designed to account for the reduction in light output from a lighting system due to: the ageing of the lamps and the accumulation of dirt and dust on the light fittings and room surfaces.

Protection types for technical luminaries

1. ClassprotectionBefore a lighting protection system is planned, the object to be protected must be assigned to one of four lighting protection classes. Efficiency in lighting protection class I is the highest at 99% and in lightning protection Class IV the lowest at 84%

ApplicationLightning protection class recommendation based on

Directive VdS 2010

EX-zone in industry and the chemicals sector

2

Computer centre, military applications, nuclear power

stations

1

Photovoltalk buildings > 10 kW 3

Museums, schools hotels with more than 60 beds

3

Hospitals, churches, storong facilities, meeting places

accommodating more than 100 to 200 people

3

Administration buildings, sales outlets, office and bank buildings with over 2,000 m2

3

Residential buildings with more than 20 apartments, multi-

storey buildings over 22 m high

3

class 0 Protection is provided exclusively by the main insulation. If the basic insulation should fail, the insulated environment surrounding the fixture will prevent current from flowing to the user. In this case, the fixture does not have two protection levels, therefore there are national plant standards that prohibit the use of class 0 fixtures.

class I Protection, other than through the main insulation, is provided by the permanent connection of the accessible conducting parts (shields, shades, structures) to a protection conductor, i.e. the earth conductor. If the main insulation should fail, the protection against electric shock is guaranteed by the earth system. In this case, the fixture has two protection levels: the main insulation and the earth system.

class II Protection, other than through the main insulation, is provided by the use of double insulation or reinforced insulation. In the first case, if the main insulation should fail, protection is guaranteed by the additional insulation that encloses the parts already in the main insulation. Therefore, also in this case, the fixture has two protection levels: the main insulation and the additional insulation. Reinforced insulation is provided by increasing the distances between the active parts and the accessible parts of the fixture as indicated in the lighting fixture standard EN-60598.

class III

This class includes the fixtures fed at voltages of less than 50V. In this case, protection is provided by the type of power supply of that fixture (low voltage). It has been demonstrated that these low voltages are not dangerous for the user.

2. IP-IngressProtectionRatingsIP - Ingress Protection rating is used to specify the environmental protection - electrical enclosure - of electrical equipmentIngress Protection (IP) ratings are developed by the European Committee for Electro Technical Standardization (CENELEC) (NEMA IEC 60529 Degrees of Protection Provided by Enclosures - IP Code), specifying the environmental protection the enclosure provides.The IP rating normally has two (or three) numbers:1. Protection from solid objects or materials 2. Protection from liquids (water) 3. Protection against mechanical impacts (commonly

omitted, the third number is not a part of IEC 60529)Example - IP Rating*With the IP rating IP 54, 5 describes the level of protection from solid objects and 4 describes the level of protection from liquids.An “X” can used for one of the digits if there is only one class of protection, i.e. IPX1 which addresses protection against vertically falling drops of water e.g. condensation.

Protection against ingress of solid foreign bodies as per first digitIP 0x unprotected against ingress of solid foreign bodies.IP 1x protection against solid bodies >50-mmIP 2x protection against solid bodies >12-mmIP 3x protection against solid bodies >2.5-mmIP 4x protection against solid bodies >1 mmIP 5x dust-proofIP 6x dust-tightProtection against moisture as per second digitIP x0 ordinary – not protectedIP x1 drip-proofIPx2 protection against water drops falling up to 150 from the verticalIPx3 rainproof – protection up to 600 from the verticalIPx4 splash-proofIpx5 jet-proofIPx6 protection against heavy seas (conditions on ship’s deck)IPx7 watertight (immersible)IPx8 pressure-watertight (submersible)

IK protectionProtection type IK indicates the protection degree of the operating devices provided by the housing against mechanical load:The operating device’s level of protection against detrimental mechanical stress provided by the housing and verified by standardized test methods.In general, the protection level applies to the housing as a whole. Where parts of the housing show different protection levels, they have to be marked separately.Structure of the IK code:Code letters (international mechanical protection) distinctive group of figures (00 to 10) When higher load energy is required, we recommend 50 joule.Required energy in joule with:

IKcode IK00 IK01 IK02 IK03 IK04joule * 0,15 0,20 0,35 0,50

IK05 IK06 IK07 IK08 IK09 IK100,70 1,00 2,00 5 10 20

*not protected by current standard.

Lighting Terminology | 1110 | Lighting Terminology

Daylight factorUnder a standard CIE overcast sky, the illuminance outside. Proportion to the illuminance inside. This proportion is defined as the daylight factor and is expressed as a percentage.Daylight factor cannot be measured in real building, since the distribution of luminance across the real sky changes continuously, and very rarely approximates a standard CIE sky.

Daylight intergrationThe art and science of integrating lighting design, lighting controls and shading systems into the forms and finishes of systems into the forms and finishes of a building, to achieve the desired degree of contrast and brightness in the interior at all times of the day and year.

Average day light factor (DF) A measure which describes how “well daylight” a room will appear. Cannot be measure in real rooms , but is only defined under a CIE standard sky in tests on model buildings. Where:T= transmittance of glazing W= windows areaQ = vertical angel of sky seen from centre of window M= maintenance factor A=total area weighted surfaces R = area-weighted surfaces If the average daylight factor is less than 2% then the room will appear gloomy, and the artificial lighting should be bring contrasty, stimulating and perhaps colourful to make up for the lack of daylight- linked lighting controls should be considered in order to save energy and reduce daylight.

Light Output Ratio (LOR)The ratio of the total light output of a luminaire, compared with total lamp light output.

LOR = Out of luminaireOut of lamp

Dlor (Downward light output ratio)The number of lumens leaving a luminaire at an angle below the horizontal, divided by the number of lumens which originally left the lamp. The result is a dimensionless quantity expressing the “downward efficiency” of the luminaire. luminance can be so large that the contrast and therefore the visibility of the task is reduced.Example The total, upward and downward lamp output from a lamp are 1000 lm, 300 lm and 500 lm respectively. Calculate upward light output ratio (ULOR), downward light output ratio (DLOR), light output ratio (LOR) of luminaire and percentage of light energy absorbed in luminaire.

ULOR = 300 = 0.3 or 30%1000

DLOR = 500 = 0.5 or 50%1000

LOR = 300+500 = 0.8 or 80%1000

Flux Fraction A number used to describe the effect of lighting in a space. Defined as the ratio of indirect to direct light from a single luminaire, or from the combined effect of many luminaires. For a single luminaire, divide the ULOR by the DLOR to obtain FFR.

Gloom A subjective term. Usually used to describe interiors with little visual variety or with a low average luminance on vertical surfaces

Scotopic Conditions in which the average luminance of the visual field is below 0.01 cd/m2. Below 0.01- cd/m2, cone cells are no longer used for vision, and because rod cells are more sensitive to blue light than are cone cells, blue light is comparatively brighter under scotoplc conditions than under mesopic or photopic..

Mesopic Conditions in which the average luminance of the visual field is between 0.01 and 10 cd/m2.. As the light drops below 10 cd/m2, the sensitive rod cells begin to contribute to vision. Because rod cells are comparatively more sensitive to blue light than are cone cells, blue light is comparatively brighter under mesopic conditions than under photopic. For this reason, lamps with a blue appearance are more effective in low- light situation such as car parks or street lighting.

Metamerism A phenomenon in which two differently-coloured surface may appear to be the same colour, when lit by a certain light sources such as multiphosphor fluorescent or high-pressure sodium lamps are used. Metamerism is comparatively likely under tri-phosphor fluorescent tubes which have narrow spectral outputs. Metamerism is not directly related to colour rendering index.

Room index A measure of the shape of a room for lighting purposes. Defined as the total area of horizontal surface (floor plus ceiling) divided by the total area of vertical surfaces (walls). Room index is used to determine the utilization room since lower and wider rooms (with high room indices)result in better utilization factors.

K=LB

hlb(L+B)

Where:hLp= mounting height of luminaires above working plane.

Beam angle Lamps (and occasionally luminaires ) with narrow beams are described in terms of their beam angle. The illogical and confusing practice of quoting the angular diameter (rather than the angular radius) of the beam has became common in Britain and America. Thus a “24 beam” is actually a 2 x 12

beam, where the angle between the axis and the edge of the beam is 12. The edge of the beam is usually taken as the angle at which the intensity drops to half its peak value. Occasionally, the angle at which the intensity drops to one tenth of peak value is used instead.

Shielding angle The angle of elevation (measured from the downward vertical) above which direct light from a luminaire must be shielded by a louver or diffuser. Shielding angles for indoor workplaces are given in EN 12464. The shielding angle is dependent upon the luminance of the lamp most linear fluorescents lie in the first (1-20 kcd/m2) band, where as most compact fluorescent lie in the second halide lamps lie in the fourth band (>500kcd/m2).

Solid angle (steradians) Solid angle is used to define the intensity of a source, i.e. how much light it gives in a particular direction. Intensity is measured in lumens per sterdians.

Solid angle

€

ΩA sphere contains 4p (=12.6) steradians, so a hemisphere contains 2

€

Π , etc. The steradian is also used in day light calculations, to calculate the horizontal or vertical illuminance under –neath a sky. E= Lcos

€

ΦdΩ

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Simes:SIMESS.p.A., established in 1973 by Cav. Egidio Botti, is an avant-garde company dedicated to the design and production of superior outdoor lighting systems. Ever since its foundation, SIMES S.p.A. has been evolving in the research of front-running technology and high quality products. High quality standard, the choice of the best materials such as aluminium and glass, and great care over light control to create sensational lighting effects: all these elements combine to summarize the company motto. Roberto Botti, Cav. Botti’s son currently the General Manager, takes the head during the nineties and, thanks to his well-established experience as the Company Export Manager, brings new ideas to the Company and starts up the development of new products. The first lines of in-ground recessed luminaires, either walk-over or drive-over, wall-recessed devices and bollards come to life: in a few years these strategic segments allow SIMES S.p.A. to reach quality excellence and market recognition.

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DesignoplisCairo is witnessing a new landmark in its urban and economic landscape with the establishment of Designoplis, a new shopping destination for home and office furniture, furnishings and all design related products and services. Its location, concept and overall prospects are unfolding to become a story of success.With the belief in the rise of design today as a concept and form of art and with the legacy of the ancient Egyptian civilization in codifying design elements in art amd architecture, Designoplis celebrates its uniqueness. With an array of categories, service outlets as well as leisure addition

38, 40 Beirut Street, Heliopolis,Cairo EgyptP.O. Box 468 Heliopolis.Tel: (202) 22564030 - 24505522 - (2012) 7411779Show Room: (202) 24528486 Fax:(202) 24520799info@siraj-lighting.com

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