Light+Vocabulary


 * Vocabulary**
 * **Accent Lighting:** Directional lighting to emphasize a particular object or draw attention to a display item.
 * **Ballast**: an electrical device used wite fluorescent and HID (high intensity discharge) lamps (light bulbs) to supply sufficient voltage to start and operate the lamp but then to limit the current during operation
 * **Cathode:** Metal filaments that emit electrons in a fluorescent lamp. Negatively charged free electrons emitted by the cathode are attracted to the positive electrode (anode), creating an electric current between the electrodes.
 * **Chromaticity:** Measure to identify the color of a light source, typically expressed as (x,y) coordinates on a chromaticity chart.
 * **Core:** Component of electromagnetic ballast that is surrounded by the coil. Core is comprised of steel laminations or solid ferrite material.
 * **Core & Coil Ballast:** A ballast that uses a "Core & Coil" assembly to operate fluorescent or HID lamps. Refers to copper windings on a steel core.
 * **Daylight Harvesting:** Lighting design for building interiors that makes of daylight as a way of reducing energy consumption.
 * **Dimmable:** Whether or not the lamp lumens can be varied while maintaining reliability.
 * **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")
 * **Ignitor:** An electronic device providing a high voltage pulse to initiate an electrical discharge. Typically, the ignitor is paired with or is a part of the ballast.
 * **Quartz:** A name for fused silica or melted sand from which many high-temperature containers are fashioned in the lighting industry. Quartz looks like glass but can withstand the high temperatures needed to contain high intensity arc discharges.
 * **Task Lighting:** Supplemental lighting provided to assist in performing a localized task, e.g. a table lamp for reading or an inspection lamp for fabric inspection.
 * **Troffer:** A long, recessed lighting unit, usually installed in an opening in the ceiling.
 * **Valance Lighting:** Lighting from light sources on a wall typically above eye level, shielded by horizontal panels. The light may be upward or downward directed.