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The Lamp and the Luminaire are separate concepts and have separate properties. Lamps are the elements that generate the light. Luminaires are the instruments that house and control the lamp. Lumens is a measure of the light generated by the lamp. Effective lumens is a measure of the amount of light directed at a target.
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The lamp, often called the 'light bulb', provides the source of the light.
Lamps use a variety of electro-chemical processes to generate electromagnetic radiation.
Lamp properties include the spectrum of light generated and the efficiency and tradeoffs.
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Lamps can be rated by their efficiency which measures the light generated (in lumens) for the power supplied.
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Each type of lamp generates light of a characteristic color. The spectrum of light emitted (the combination of colors) is determined by the physical principals of the materials in the lamp.
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Incandescent
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Wide Spectrum, low efficiency
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Flourescent
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Wide Spectrum, higher efficiency
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Metal Halide
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Multiple spectrum high intensity discharge, higher efficiancy
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Mercury Vapor
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Blue-white light, lower efficiency
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Low Pressure Sodium
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Narrow Spectrum, highest efficiency
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High Pressure Sodium
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Orange light, wide spectrum, higher efficiency
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The Luminaire provides the physical and electrical connections and needed to house and activate the lamp and to shape and direct their light through reflection and dispersion onto the target.
Luminaires come in all shapes and sizes and provide a decorative addition to all environments where lighting is desired.
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Let's consider a common luminaire, the table lamp. Most table lamps use an incandescent bulb, have and on/off switch and plug into a standard electrical outlet.
Most table lamps are shaded to prevent glare and to disperse the light to provide indirect lighting.
The lamp has areas of direct and indirect lighting.
Outside luminaires are the same, except they are mounted to buildings and other structures and have a world to light.
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Recessed luminaires provide full cutoff to minimize uplighting and glare. Efficiency is increased because stray light is minimized.
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Shielded models aid in shaping the direction of the light to increase the effecive efficiency.
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