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MacAdamEllipse A region on the CIE chart where all colors are indistinguishable to human vision. Some regions are referred to as multiple "step" MacAdam Ellipses. These regions contain colors, which can be distinguished by a given amount to the human eye. A two-stepMacAdam Ellipse contains colors that are only slightly different to human vision, a three step more so, etc. Motion Sensor A device that senses motion, can be used to control power to a light source MR LAMP Multi-facet reflector lamp, of which the most popular is the MR16. MSCP (Mean Spherical Candle Power) unit of measure that represents the average output of a light source measured in all directions. Nanometer (nm) Unit of measurement equivalent to about 1 billionth of a meter. The wavelength of visible light ranges from 400 to 700 nanometers NEC National Electrical Code Sets standards for wiring and electrical devices. The NEC requirements are widely followed by local jurisdictions. Network A system of dimming controls that are wired and programmed to respond together, usually to link controls in several rooms. Optics The science that deals with the properties of light; specifically dealing with the way light changes directions when it is either refracted and dispersed by a lens or reflected from a mirror PAR Lamp (Parabolic Aluminized Reflector) A standard in directional, screw type lamps; the number following PAR indicates eighths of an inch in diameter Phosphor A chemical compound designed to absorb light and convert it into other wavelength(s); used in white LEDs to convert the single emitted wavelength into a broader spectrum Photo Cell Light-sensitive device used to control the output of a fixture based upon ambient lighting conditions. Photometry The measurement of quantities associated with light; useful in selecting or comparing lighting products Pixel Term used in video applications to denote one-color controllable element in an image Power Supply A power supply is an enclosed component that supplies and regulates power to an electrical device. It receives power from an electrical source and regulates the output voltage and current PWM (Pulse width modulation) A method of dimming control achieved by varying the duty cycle of the power supply Radiant Flux Total radiant energy per unit time, unadjusted for eye sensitivity; standard unit for radiant flux is a watt (W) Reflector An optical device used to control the directionality of a light source Resolution The number of pixels contained in a display, expressed in terms of the number of pixels on the horizontal axis and the number on the vertical axis; the sharpness of the image on a display depends on the display’s resolution and size Retrofit Upgrading a fixture, room or building by installing new lighting fixtures, parts or equipment.

Solid State The electronic properties of crystalline (generally semiconductor) material Spot Light A lamp or fixture with a tight beam of light T 1 3/4 Lamp (5mm) A 5mm diameter LED with a through hole lead frame T1 Lamp (3mm) A 3mm diameter LED with a through hole lead frame. Task Lighting Usable light intended to illuminate a surface for specific work functions Thermal Resistance The resistance of a substance or material to the conduction of thermal energy, or heat. Triac A method of dimming control commonly found in homes and commercial buildings Troffer An inverted trough suspended from a ceiling as a fixture for fluorescent lighting tubes UL Underwriters Laboratory. An independent org. whose responsibilites include rigorous testing of electrical products. When products pass these test, they can be labled and advertised as UL Listed. UL tests for product safety UV Ultraviolet the range of nonvisible radiation wavelengths from 4 nanometers, on the border of the x-ray region, to 380 nanometers, just beyond the violet in the visible spectrum. VAC Volts of Alternating Current VDC Volts of Direct Current Valance Lighting Lighting from light sources on a wall typically above eye level,shielded by horizontal panels; the light may be directed upward or downward Viewing Angle The position left/right and up/down of vertical axis where the luminous intensity reduces to 50 percent of its peak value Wall Washing A lighting technique in which a wall is evenly washed with light. Warm White A lower CCT white, typically from 2,700°K to 3,800°K, which appearsas a yellowish-white light Watt The unit of electrical power Wavelength The distance between two consecutive peaks of a wave; the wavelength of visible light is between 400 nm to 700 nm

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