Light+Vocabulary

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

====**Ballast **  An auxiliary piece of equipment required to start and to properly control the flow of current to gas discharge light sources such as fluorescent and high intensity discharge (HID) lamps. Typically, magnetic ballasts (also called electromagnetic ballasts) contain copper windings on an iron core while electronic ballasts are smaller and more efficient and contain electronic components. ====

====**Bayonet** A style of bulb base which uses keyways instead of threads to connect the bulb to the fixture base. The bulb is locked in place by pushing it down and turning it clockwise. ====

====**Bulb** A loose way of referring to a lamp. "Bulb" refers to the outer glass bulb containing the light source. ====   **ChromaFit** A GE brand name for metal halide lamps designed to operate on HPS ballasts, allowing a user to switch from the yellowish color of HPS to the white color of metal halide without changing ballasts. These products are available in both quartz metal halide and ceramic metal halide (CMH) versions.   **Coil** Windings of copper or aluminum wire surrounding the steel core in ballast. Also refers to the entire assembly comprising the inductor or transformer.   **<span style="font-family: Tahoma,Geneva,sans-serif;">Induction Lighting **<span style="font-family: Tahoma,Geneva,sans-serif;">Gases can be excited directly by radio-frequency or microwaves from a coil that creates induced electromagnetic fields. This is called induction lighting and it differs from a conventional discharge, which uses electrodes to carry current into the arc. Induction lamps have no electrodes inside the chamber and generally, therefore, have longer life than standard lamps. Genura® is an example of an induction lamp. PhotometryThe measurement of light and related quantities. <span style="background-color: #ffffff; color: #666666; display: block; font-family: Arial,Helvetica,san-serif; font-size: 15px; text-align: left;"> <span style="background-color: #ffffff; color: #666666; display: block; font-family: Arial,Helvetica,san-serif; font-size: 15px; text-align: left;"> <span style="background-color: #ffffff; color: #666666; display: block; font-family: Arial,Helvetica,san-serif; font-size: 15px; text-align: left;">**<span style="font-family: Tahoma,Geneva,sans-serif;">Spacing to Mounting Height Ratio **<span style="font-family: Tahoma,Geneva,sans-serif;">Ratio of fixture spacing (distance apart) to mounting height above the work plane; sometimes called spacing criterion. It is OK to have fixture spaced closer than the spacing criterion suggested by the manufacturer but not farther, or you will get dark spots in-between fixtures. Torchiere: a tall floor lamp that provides indirect lighting with its light source located within a reflecting bowl that directs the light upward, which then reflects off the ceiling <span style="background-color: #ffffff; color: #666666; display: block; font-family: Arial,Helvetica,san-serif; font-size: 15px; text-align: left;"> <span style="background-color: #ffffff; color: #666666; display: block; font-family: Arial,Helvetica,san-serif; font-size: 15px; text-align: left;"> <span style="background-color: #ffffff; color: #666666; display: block; font-family: Arial,Helvetica,san-serif; font-size: 15px; text-align: left;">**<span style="font-family: Tahoma,Geneva,sans-serif;">Wall Washing **<span style="font-family: Tahoma,Geneva,sans-serif;">A lighting technique that produces a relatively smooth, even level of illumination on a wall that minimizes the apparent texture of the surface