Unit of illuminance – light falling on a surface. One lumen falling on one square foot equals one-foot candle. Also, a measurement of the amount of light reaching a surface.
The amount of light that a lamp/bulb produces. Unit of output; technically – Luminous flux.
Bright lighting that causes discomfort and impairs good visibility. Possible causes may be light sources that are too bright for the application, or fixtures that may not conceal bulbs sufficiently, among many others.
A unit of electrical power.
The amount of electricity consumed by a lamp/bulb.
KWH. A unit of measurement for electrical energy. One kilowatt hour equals 1000 watts of energy used for one hour.
Light Emitting Diode. A small, solid state device used to indicate dimmer or control status; also used in signs and control units.
Electronics that use semi-conductor chips and circuitry.
Control that uses passive infrared or ultrasonic detection to sense whether someone is present or not, and to turn a light on or off appropriately. Commonly used in outdoor flood or spot fixtures. “Automatic On” sensors turn lights on when presence; “Manual On” sensors require you to press a switch. Both types turn lights off automatically when they no longer sense a presence.
Light-sensitive device used to switch fixtures on & off according to available daylight.
The point in hours where 50% of a lamp type initially started will still be functioning.
Upgrading a fixture, room or building by installing new fixtures, parts or equipment.
Underwriters Laboratory. Commonly referred to as “UL”. An independent organization whose responsibilities include rigorous testing of electrical products. When products pass these tests, they can be labelled and advertised as “UL Listed”. UL tests for product safety only.