Light_Vocabulary


 * __Cathode __**: an electrode that emits electrons. A fluorescent lamp cathode emits or discharges electrons to the cathode at the other end of the lamp (light bulb).


 * __Bi-Pin __**: any base with two metal pins for electrical contact. This is the typical base for a fluorescent tube of 1 to 4 feet in length. It consists of 2 prong contacts which connect into the fixture. Medium bi-pins are used with type T-8 and T-12 tubular fluorescent lamps, and miniature bi-pins are used for tubular T-5 fluorescent lamps.


 * __ANSI ( American National Standards Institute) __**: consensus-based organization which coordinates voluntary standards for the physical, electrical and performance characteristics of lamps, ballasts, luminaires and other lighting and electrical equipment.


 * __Core __**: component of electromagnetic ballast that is surrounded by the coil. Core is comprised of steel laminations or solid ferrite material.


 * __Flood __**: used to refer to the beam pattern of a reflector lamp, which disperses the light over a wide beam angle, typically 20 degrees or more. ("Flood" as opposed to "spot")


 * __Lumens __**: a measure of the luminous flux or quantity of light emitted by a source. For example, a dinner candle provides about 12 lumens. A 60-watt Soft White incandescent lamp provides about 840 lumens.


 * __Scotopic __**: vision where the rods of the retina are exclusively responsible for seeing, typically like the light levels in the countryside on a moonless, starlit night


 * __Snoot __**: a protruding hollow cone of opaque material that provides a high cut-off angle for certain types of track fixtures, landscape lights, or spotlights. A snoot focuses light into a small area and is often used in art gallery lighting, landscape lighting, or theater lighting.


 * __<span style="color: black; font-family: 'Trebuchet MS',sans-serif; font-size: 12pt;">Faceplate __**<span style="color: black; font-family: 'Trebuchet MS',sans-serif; font-size: 12pt;">: the metal or plastic plate installed over an on/off switch, dimmer, or receptacle, which covers the wall opening and protects the wiring inside the junction box.