| BAFFLE | A single opaque or translucent element to shield a source from direct view at certain angles, or to absorb unwanted light. |
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| BEAM ANGLE | The angle between the two directions for which the intensity (candlepower) is 50% of the maximum intensity as measured in a plane through the nominal beam centerline |
| BRIGHTNESS | The extent to which a luminary emits more or less light. |
| CURRENT | An electric current is a stream of charged particles, such as electrons or ions, moving unidirectionally through an electrical conductor or space. Its unit is Ampere (A) |
| CANDELS, CD | The unit of measure indicating the luminous intensity (candle-power) of a light source in a specific direction; any given light source will have many different intensities, depending upon the direction considered. |
| CATWALK | A raised overhead platform used for mounting and accessing luminaires. |
| CHROMATICITY | The quality of a color regardless of its luminance as determined by its hue and saturation.
Color Rendering or Color Rendering Index (CRI): It is the ability of a luminary to reproduce surface colors accurately. The higher the CRI rating, the more accurately colors will be reproduced. |
| COEFFICIENT OF VARIATION (CV) | CV is defined as the ratio of the standard deviation of all values to the mean (average) value.A measurement of illuminance uniformity. It is a metric used to measure uniformity in sports lighting. |
| DIFFUSER | A device to redirect or scatter the light from a source by the process of diffuse transmission. |
| DMX | DMX is an acronym for Digital Multiplex. It is the standard digital communication protocol that is used to remotely control intelligent lighting fixtures |
| DRIVER | An electronic circuit that controls and regulates current through MCPCB of LED luminaires. |
| DIRECT LIGHTING | Lighting by luminaires distributing 90 to 100 percent of the emitted light in the general direction of the surface to be illuminated. The term usually refers to light emitted in a downward direction. |
| EFFICACY | The parameter to measure the effectiveness of a light source. Measured in lumens/watt. |
| ELECTROMAGNETIC INTERFERENCE (EMI) | Electromagnetic INTERFERENCE occurs in the radio frequency (RF) range, radiated by fluorescent lamps and electronic circuits. |
| FLICKER | The visible temporal variation of emitted light by luminaries. |
| FREQUENCY | The number of times per second that an alternating current system reverses from positive to negative and back to positive, expressed in cycles per second or hertz, Hz. |
| GHOSTING | An effect that occurs when off state luminaries faintly glow because of residual voltage in the circuit. |
| GLARE | The light that causes discomfort or reduces the ability to see |
| HEAT SINK | A part of the thermal management system in the luminaries that conducts or convects heat away from the drivers circuit and LEDs. |
| HARMONIC | An electrical frequency that is an integer multiple of the fundamental frequency; for example, if 60 Hz is the fundamental frequency, then 120 Hz is the second harmonic and 180 Hz is the third harmonic; some electronic devices, such as ballasts or power supplies, can cause harmonic distortion, directly affecting power quality. |
| High Intensity Discharge (HID) Lamps | A general group of lamps consisting of mercury, metal halide and high pressure sodium lamps. |
| INDIRECT LIGHTING | Lighting by luminaires distributing 90 to 100 percent of the emitted light upward. |
| IP RATINGS | “IP” stands for Ingress Protection. IP ratings have two numbers: the first stands for the protection against solid objects, the second for protection against liquids. |
| KELVIN | Kelvin (°K) is a unit of measurement for temperature and is often used in the measure of the color temperature of light sources. |
| LUX | The amount of light a luminaire delivers to a surface. Sometimes it is also measured in foot candles (fc). 1FC=10.7639 Lux |
| L70 HOURS | LED’s expected light output in percentage over its stated life span. “L70” predicts when the LED reaches 70% of the initial lumen output. |
| LIGHT TRESPASS | Spill light is cast where it is either annoying or unwanted. |
| LIGHT LOSS FACTOR (LLF) | A factor used to calculate luminance over a given period and under given conditions using light loss due to temperature and voltage variations, dirt accumulation on the luminaire, lamp depreciation, maintenance procedures, and atmosphere conditions. |
| LUMEN | Lumen is a measure of the total “amount” of visible light emitted by a LED. |
| LOUVER | A series of baffles used to shield a source from view at certain angles or to absorb unwanted light. |
| LUMEN MAINTENANCE CURVE | A graph illustrating the predicted average light output behavior over time |
| OBTRUSIVE LIGHT OR SPILL LIGHT | Uncontrolled light that is directed up into the sky or beyond the boundary of an illuminating area |
| POWER | power is the amount of energy transferred or converted per unit time. Its unit is Watt (W) |
| POWER FACTOR (PF) | Power factor is a measure of how efficiently electrical power is being used. |
| PULSE-WIDTH MODULATION (PWM) | Pulse-width modulation uses a rectangular pulse wave whose pulse width is modulated resulting in the variation of the average value of the waveform. |
| REFLECTOR | A device used to redirect the light by the process of reflection. |
| THERMAL MANAGEMENT | Controlling the operating temperature of the luminary |
| TILT FACTOR | This factor is a function of the lamp position for the lighting fixture |
| UNIFORMITY RATIO | It is a ratio of minimum to average lux. Design criteria to assure that light is distributed evenly across the entire field. |
| UNIFORMITY GRADIENT (UG) | Rate of change of illuminance between adjacent (grid) values. |
| VOLTAGE | Voltage is the pressure from a power source that pushes charged electrons (current) through a conducting loop, enabling them to do work such as illuminating light. Its unit is Volt (V) |
| WORK PLANE | The plane at which work usually is done. |
