Lighting PDF

1  Aim of the Module To understand – What is Light? Lighting Importance – Security Perspective Description of Light terms Lighting Systems Lighting Economics Starting and Restrike Different types of lamps Security Applications...

1  Aim of the Module To understand – What is Light? Lighting Importance – Security Perspective Description of Light terms Lighting Systems Lighting Economics Starting and Restrike Different types of lamps Security Applications Confidential 2  What is Light? Physics Says – Light is an Electromagnetic radiation. Perceived by Human eye. Natural Light Artificial Light Light generated naturally. Light generated using man- Sun is one such source. made technologies. Incandescent and Luminescent Lights. Confidential 3  Lighting? Provide Light. Deliberate use to Daylight – Natural Bulbs/ Lamps are used achieve Light achieved by in the absence of Sun. Daylight. practical/aesthetic effects. Confidential 4  Why is it important from the perspective of Security? Security lighting serves three primary functions - Deterrent - criminal activities. Provides life-safety functions. Detecting mechanism in an area. Lights up the area for VSS. Confidential 5  Different terms that describe and express Light Luminous flux – The total amount of visible light emitted by a source per unit of time. Measured in Lumens. Lumens –Power of the source to produce light. Lux – No. of Lumens produced per square meter. Foot candle – No. of Lumens produces per square feet (1fc = 10.76 Lux). Difference between Lumens and Lux Confidential 6  Different terms that describe and express Light Illuminance – Concentration of light in a particular area. Light falling onto a surface. Luminance – How much light comes off of a surface and reaches your eye. Compare white wall to a black wall. Measured in candelas per square meter. Difference between illuminance and Luminance Confidential 7  Color Temperature It is the measure of the warmth or coolness of the light. It is measured in Kelvin (K). 0 K = -272⁰ C Generally people always perceive red to be warmth CCT and blue to be Cool, but it’s the opposite. Color temperature also has a considerable effect on the mood of the person and ambience of the surrounding. Confidential 8  Color Rendition The ability of the lamp to faithfully reproduce the colors seen in an object. It is measured as a Color Rendition Index (CRI) on the scale of 0 to 100. Identification – apprehension and prosecution. CRI CRI application CRI Short Confidential 9  Brightness – Human Perception of the amount of light that reaches one’s eyes. Glare Negative Positive Excessive brightness that Affects the patrolling Glare can be used hurts the eyes and can and response forces. effectively to deter affect its efficiency. it may cause light unauthorized It creates excessive contrast trespass onto activity at the site with the other objects and adjoining properties, perimeter. makes people turn their including sidewalks and roadways. heads away. It is important that light trespass not cause glare or excessive contrast to drivers and pedestrians, both on and off the organization’s property. Confidential 10  Lighting Economics The cost is a major factor in deciding the level of light system that will be installed for security and safety. This cost depends on the following - Efficacy – The ratio of the amount of visible light output per unit of electricity. + Maintenance cost which includes the labor to clean and replace the lamps. Cost of Different 100 W Bulbs in India Type of Bulb Approximate Cost (₹) Incandescent ₹30–₹50 Halogen ₹150–₹250 CFL (Compact Fluorescent) ₹250–₹400 Fluorescent Tube (T8) ₹300–₹500 LED ₹400–₹800 Metal Halide ₹500–₹800 High-Pressure Sodium ₹700–₹1,200 Low-Pressure Sodium ₹1,000–₹1,500 Mercury Vapor ₹600–₹900 Confidential 11 Confidential 12  Starting and Restrike Time Some lamps require time to relight if they are switched off intentionally or by a full power failure or a brownout. The relighting is of HID (High Intensity Discharge) Lamps which require the lamp tube to cool down sufficiently. HID lamps take time to go from cold to the desired temperature to start. High-intensity discharge lamps (HID lamps) are a type of electrical gas-discharge lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube Confidential 13  Lighting System The Lamp - Evolution The Luminaire -Explain Difference between Lamp and Luminaire Confidential 14  Mounting Hardware – Wall Brackets, street Lights, etc. Electrical Power operates- The Lamps. Ballasts - Device placed in series with a load to regulate current in an electrical circuit. Photocell - Device that is used to detect and measure light. Ballasts Confidential Photocell 15  Incandescent Lamp Based on the principle of incandescence, which means that light emission is caused due to heating of the filament. Its Efficacy is 20 and Life is 1000 – 4000 hours. Working The current is supplied throughout a thin metal filament. Once the filament is heated then it glows to generate light. These lamps use a tungsten filament due to their high melting point. The filament in this bulb can reach 4,500 degrees F temperatures. A glass enclosure avoids oxygen within the air from reaching the filament otherwise the filament gets overheated & oxidized within seconds. Incandescent Lamp Working Confidential 16  Not energy efficient. Lifespan is low as compared to other lamps. Low Efficacy. Not suitable for large areas. Applications Used in table lamps, desk lamps, hallway lighting, accent lighting, chandeliers, closets, etc. Used in commercial & household lighting. Confidential 17  Halogen Lamps Construction Consists of a filament of tungsten metal, which is enclosed in a fused silica quartz glass. Glass cover of the lamp is filled with an inert gas like argon and nitrogen to prevent oxidation. Use of halogen gas like bromine and Iodine at low pressure in the lamp reduces the uneven evaporation of the filament and darkening of the glass cover. Working Electric current passes through the filament (tungsten) causing it to heat. This increases the temperature and thus the filament emits light. Due to high temperature the tungsten filament starts to Halogen Lamp Working evaporate. The evaporated tungsten combines with the halogen gas and gets deposited back on the filament. This is known as halogen cycle which increases the lifespan of the lamp. Confidential 18  The lamp gets extremely hot due to high temperature making it a fire hazard. Could potentially explode due to high pressure, sending glass shards outward. Applications Used as public hall lighting, projection lamps ,headlamps in vehicles, inspection lights and microscope illuminators, etc. Used for factory lighting and as airport runways lighting, etc. Confidential 19  Fluorescent Lamp (Electric Discharge Lamp) Construction The lamp is made in the form of a long tube whose inside walls are coated with some phosphor. The tube is filled with a small amount of mercury vapor and a small amount of argon gas. At both ends of the tube, the electrodes are attached. The electrodes are of spiral form, made of tungsten and coated with an electron emitting material. The choke is connected to provide the lamp with voltage impulse and the lamp filament is connected to a starter which acts as a cathode glow lamp with bimetallic strips at the electrodes. Working A high potential difference between the filaments ionizes the mercury and argon present inside the lamp tube and results in the passes of current between the two electrodes inside the tube. Working of a fluorescent lamp The excited mercury vapor in the tube produces ultraviolet rays, which are falling on the phosphor coating results in fluorescence, i.e., visible light is emitted from the phosphor coating. Confidential 20  Contains Toxic Material. Light from Fluorescent lamp is omnidirectional causing the wastage of certain percentage of light. Emits UV Rays. Negative environment impact and increased cost of recycling. Applications Used in hallways, kitchen, rooms, basement, garages, etc. Majorly used indoors. Confidential 21  Metal halide Lamp Construction MH Lamps are made up of several components, mainly - Glass tube – that encloses the arc tube protecting it form air and moisture, made of Borosilicate which also helps to filter out UV rays produced by the arc. Arc Tube – Consists of two tungsten electrode, gas mixture (combination of argon gas, mercury vapor, and metal halides that fills the arc tube.) When electric voltage is applied to the metal halide lamp, the argon gas in the lamp is ionized and facilitates striking of the arc across the two electrodes. The heat produced by the arc vaporizes the mercury and metal halides which produces light when the temperature and pressure increase. The nature of the metal halides affects the nature of light produced by the lamp. To reach the full light output, metal halide lamps require around 3 to 5 minutes. Working of MH Lamps Confidential 22  High Start and Restrike time. Expensive and require special fixture. High operating temperature causing excess heating of lamp components. Applications Used both indoors and outdoors. Commercial, sports arena, parking lot, factories, residential security lighting, etc. Confidential 23  Mercury Vapor Lamp Construction It consists of 2 electrodes made up of an alloy of tungsten which is placed together in a medium containing mercury vapor and argon gas. These electrodes are enclosed in an elliptically shaped glass tube made up of borosilicate. The external circuit connections from the bulb are given to the ballast and the ignitor (generates voltage pulses for the lamps). Working When the supply is switched ON, the initial discharge is established between electrodes main electrode (ME) 1 and auxiliary electrode due to ionization of argon gas and then between electrodes ME 1 and ME 2. The heat produced due to this discharge is sufficient to vaporize mercury and discharge through the mercury vapor takes place. In this normal operation of the lamp, it emits or radiates its characteristics light. Discharge - Release and transmission of electricity in an applied Electric field through a medium such as gas. Confidential 24  High Start and Restrike time. Expensive and require special fixture. Voltage sensitive. Life threatening if leaked due to the use of mercury. Applications Used in industrial area, street lights, yards, garage, storerooms, security areas, etc. Confidential 25  High Pressure Sodium Vapor Lamp Construction A lamp that operates at a high pressure (above 1 atm) and temperature (above 1000 °C) inside a translucent ceramic arc tube made of polycrystalline alumina (PCA). The arc tube contains a mixture of xenon gas, sodium-mercury amalgam, and electrodes at both ends. The arc tube is enclosed in a heat-resistant outer glass bulb that is evacuated or filled with inert gas. Working The lamp works by applying a high voltage pulse from a ballast and an igniter to the electrodes, which ionizes the xenon gas and creates an initial arc. The arc heats up the arc tube and vaporizes the mercury and sodium. The mercury vapor emits a bluish-white light, while the sodium vapor emits a yellow light. The combination of these two spectra results in a golden-white light. HPS Lamp Working Confidential 26  Poor CRI. High intensity Glare. Longer start and re striking time. Applications Used in street lighting, industrial lighting, warehouses, factories, billboards, etc. Confidential 27  Low Pressure Sodium Vapor Lamp Construction The outer envelope - borosilicate glass. The inner surface - coated with indium oxide (heat reflecting allows visible light to pass and IR radiation back inside increasing Light output and temperature. The arc tube bent in U form to increase the length and contains a mixture of metallic sodium and inert gases argon and neon. Working The electrodes produce an arc and this arc strikes through the conductive gas and the lamp produces a reddish-pink light, characteristic of neon. Current flowing through the inert gas mixture of argon and neon generates heat. This heat vaporizes the metallic sodium. With the passage of time, the quantity of sodium in the arc stream increases and this produces the characteristic monochromatic orange color. Confidential 28  Poor CRI. Longer start and re striking time. Expensive to install. Applications Used for street and highway lighting as well as outdoor area and security lighting. For parking lots and garages, automobile and train tunnels, and street lighting. Confidential 29 Modern Day Light and Summary Surface Mounted LEDs What Is LED? Summary Confidential 30  Security Applications The security professional needs to consider lighting in a number of different areas of the facility being secured. General rule of Lighting Levels 0.5 fc 1 fc 2 fc Detection Recognition Identification Confidential 31  Perimeter Fencing Deterrent to unauthorized intrusion. PIDS systems along with lighting to Detect and Delay. 0.2 fc of illumination required between 02 fences. Avoid Light Trespass. Site landscape and Roadways Ground lights focused on trees/shrubs to deter the intruders from hiding. Vertical Lighting for pathway and horizontal for pedestrian identification and CCTV aid. Provides good contrast against background for detection of the intruder. Typical lighting levels are 1-4 fc for walkways, 0.5-2 fc for roadways, 10 fc for entrances and 2 fc for open yards. Confidential 32  Building Facade Floodlighting provides high Contrast for identification and of shape and movements. With good reflectance horizontal lights can be used between object and facade for good identification. lighting levels for security are 0.5-2 fc. Parking Spaces In Closed Parking Spaces for CCTVs aid luminaire design should be selected to reduce glare. A horizontal illuminance level of 5 fc with a uniformity ratio of 4:1 provides an adequate level of security. Confidential 33  Open Parking No restrictions on height of the Luminaire. (only if trees trespass isn’t tress trespass isn’t an an issue) issue) Higher light source give horizontal illumination. Minimum 0.2 fc in lesser parking and pedestrian area and 2 fc for high vehicle activity. 5 fc near vehicular access control. Loading Docks 1 fc at the building facade (roll-up doors, stairs, ramps, etc.) and 0.2 fc in open yards is recommended. For nighttime shipping/receiving – 5 fc. Loading bays – 15 fc. Packing and sorting areas – 20 fc. Packing and dispatch area – 30 fc. Confidential 34  Security Control Room Task areas – 30-50 fc. Console desk – 50 -70 fc. To avoid glare from computers luminaires to be placed at certain angles form the screen. For CCTV and alarm monitoring decreasing the ambient light to increase the contrast. Guard and Gate Houses Surrounding area – 2 to 5 fc. Task lighting in the interior during daytime – 30 fc. During night time should be low for good visibility of the surrounding. Confidential 35 Confidential 36 Security Lighting and CCTV Color Rendering Reflectance of the Directionality of the Index Material reflected lighting Wavelength of source illumination Confidential 37 Usable video signal Color Sensitivity of the CCTV camera is the lowest illuminance required to produce a specified output signal – Spectral distribution Luminance – Illuminance - - Which colors of the How much light is How illuminated light the source reflected by the is the scene? emits & its amount ? object? Total scene reflectance – How does the scene reflect light – visible bright enough to be captured Confidential 38 The amount of light necessary to produce a usable video signal (visibility of the scene in the video – how good the video is) depends on – Type & Brightness of light source Amount of light illuminating the scene The portion of light reflected from the scene The amount of light transmitted from the lens to the imager Imaging devices sensitivity Confidential 39 Confidential 40 Confidential 41 How can optimal Lighting be achieved for camera systems? 1. Ensure that the entire field of view is evenly illuminated, not just the focus area. 2. Light contours should be widely spaced. 3. Light-to-dark ratio should not be excessive. 4. Computer programs that model the expected light level from a variety of lamps can be used to assist in the initial design and layout of exterior and interior lighting. 5. Model predictions should be validated by measuring actual light levels in an area with conditions similar to the intended application 6. After implementing the final lighting design, conduct lighting surveys to - Establish a baseline light-to-dark ratio and to determine if the lighting setup meets the desired standards. 7. Periodic lighting surveys should be performed to monitor light levels. Confidential 42 Confidential 43