TYPE OF LAMP

• Lighting in a space


  • May be too bright or may come from the wrong direction, causing visual discomfort or inefficient utilization
• Means of Controlling Light

  • Reflection
  • Diffusion
  • Transmission
  • Absorption
  • Refraction
  • Polarization
• Reflection


  Light is reflected from the surface of a material. If the surface is shiny, or specular, such as surface of a mirror, the angle of reflection is equal to the angle of incidence
• Diffusion


  When the surface is matte, then the reflected light will be diffused. It may be directional or totally nondirectional
• Transmission


  When the material is transparent (clear glass), spread(etched glass), or totally diffused ( white glass), light will pass through it in a controlled mode
• Absorption


  Light is absorbed when it is directed to an opaque material or passed through a transparent or translucent material. There will be the loss of light. The amount of light absorbed is the balance of the incident light that is reflected or transmitted
• Refraction


  The direction of light changes at the interface between the two different materials such as air and glass. This is the most effective means of controlling light and is commonly used by lighting designers. This phenomenon is the basic principle of fiber optics
• Polarization


  Light travels at high speed with waves vibrating in all planes at right angles to the direction of travel. Polarizer: polarizing material (filter)
• Major Types of Lamps

  • Thermal Radiation
  • Gas Discharge
  • Electroluminescence
• Types of Thermal Radiation

  • Incandescent lamps- standard, reflector, special types
  • Halogen Incandescent lamps- standard, reflector, cap at both ends
• Types of Gas Discharge


  • Low-intensity discharge lamps-fluorescent lamps, compact fluorescent lamps, energy saving lamps
  • High-Intensity discharge lamps- Metal Halide, sodium discharge lamps, mercury discharge lamps
• Type of Electroluminescence


  • Light Emitting Diodes- LED lamps, LED modules, OLED
• Incandescent Lamps


  Produce light by the passage of an electric current through a filament, which heat it to incandescence. (e.g. general service, reflectorized and tungsten-halogen)
• Low Intensity Discharge Lamp


  Commonly type is the fluorescent lamp. It contain mercury vapor. The ultraviolet radiation excites the phosphor coating on the inside of the bulb, which emits visible light
• High Intensity Discharge Lamp


  Produce high intensity light within an inner arc tube contained in outer bulb. The metallic gas within the arc tube may be mercury, sodium or combination of other metallic vapors. Classified as mercury vapor, metal halide, high pressure sodium
• Factors to consider in selecting light sources and equipment

  • Light output
  • Intensity
  • Luminous efficacy
  • Rated lamp life
  • Luminaire efficiency
  • Lumen depreciation
  • Color temperature (Chromaticity)
  • Color rendering index (CRI)
  • Color preference index (CPI)
  • Flicker and Stroboscopic effect
  • Brightness
  • Light intensity control
  • Accessories
• Light output


  Expressed in lumens. Initial lumen, average lumen, mean lumens, beam lumens
• Intensity


  Expressed in candelas at various angles from the lamp or fixture
• Luminous efficacy


  Light output per unit of electrical power (lpw)
• Rated lamp life


  Time elapsed when 50% of a group of lamps remain burning
• Luminaire efficiency


  Ratio of the total light output of the lamps versus the total light output of all lamps in the luminaire, expressed in percentages
• Lumen depreciation


  Light output depreciates with time, loss of light known as lumen depreciation, maybe 20% to 30% of a lamp's initial light output
• Color temperature (Chromaticity)


  The color the lamp appears, expressed in kelvins (K)
• Color rendering index (CRI)


  Measure of the color shifts when standard color samples are illuminated by the light source, as compared with reference light source
• Color preference index (CPI)


  Useful in expressing the color quality of a light source on a preferential basis, such as red meat, green vegetables, blue sky, pink complexions
• Flicker and Stroboscopic effect


  The cyclic flow of a 60 Hz current through the lamp can have light fluctuations 120 times per second (flicker). When a rapidly moving object is observed the clear HID lamp, the object may appear to be at standstill or moving at lower frequencies (stroboscopic effect). Eliminated or minimized by the use of lead lag ballast for multiple lamps
• Brightness


  Physically small light sources or high intensity, such as incandescent lamps, are excellent for light control, but they can too bright for visual comfort
• Light intensity control


  Can be controlled by multilevel switching or by dimming
• Accessories


  Such as ballast, starters and dimmers
• Incandescent lamps


  Lamps using a carbon filament in a vacuum, producing 1.4 lm per watt
• Incandescent lamps


  • Use a tungsten filament in a bulb filled with inert gas
  • Most inexpensive option
  • Produce a warm and steady light that complements skin tones
  • Can be used with a dimmer
• Parts and Functions of Incandescent Lamps

  • Lead-in wire
  • Inert gas
  • Base
  • Exhaust tube
  • Pinch
  • Heat deflecting disc
  • Stem
  • Button
  • Support
  • Filament
  • Bayonet base
  • Screw base
  • Bulb
• Special Types of Incandescent Lamps

  • Globe
  • Candle
  • Flicker
  • Bullet/torpedo
  • Flame
  • Rough and Vibration Service
  • Extended life service
  • Dichroic reflector lamp
  • Krypton lamps
  • Miniature reflector (MR) lamps
• Tungsten Halogen Lamps


  Type of incandescent lamps which achieve better energy efficiency and longer life than standard incandescent lamps
• Parts and Functions of Tungsten Halogen Lamps


  • Contact
  • Base
  • Electric circuit
  • Inert gas
  • Tungsten filament
  • Filament support
  • Bulb
  • Pin
• Fluorescent Lamps


  Low intensity discharge lamps, most widely used light source in the world because they require little energy to produce a great deal of light
• Shape and Size of Fluorescent Lamps

  • T12
  • T10
  • T8
  • T5
  • T2
• Lamp color of Fluorescent Lamps


  • CW - cool white
  • D - daylight
  • WW - warm white
• CRI (Color Rendering Index) of Fluorescent Lamps


  • 9 = CRG 1A (90 - 100)
  • 8 = CRG 1B (80 - 89)
  • 7 = CRG 2A (70 - 79)
  • 6 = CRG 2B (60 - 69)
  • 5 = CRG 3 (50 - 59)
  • 4 = CRG 3 (40 - 49)
• Parts and Functions of Fluorescent Lamps

  • Mercury
  • Cathode or Electrode coil
  • Inert Gas
  • Phosphor Coating
  • Base
  • Bulb
  • Cathode Shield