Know Your Lighting ABCs … continued
Machine Blown Glass: Glass shaped by mechanically forcing air into molten glass so that it takes the shape of a mold.
Matte Finish: Lamp or fixture surface finish producing a diffuse, lightly textured dull reflection.
Mercury Vapor Lamp: A type of high intensity discharge (HID) lamp in which most of the light is produced by radiation from mercury vapor. Emits a blue-green cast of light; available in clear and phosphor-coated lamps.
Metal Halide: A type of high intensity discharge (HID) lamp in which most of the light is produced by radiation of metal halide and mercury vapors in the arc tube. Available in clear and phosphor-coated lamps.
Mission Style: Along with the Arts And Crafts movement, Mission style became popular at the turn of the 20th century. The emphasis is on simplicity, straight lines, geometric shapes and handcrafted pieces. Ornamentation may be from wrought iron, brass and woods, especially oak.
Mogul Base: Base used on high-wattage incandescent and HID lamps.
Motion Detector: 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.
MR Lamp: Multi-facet reflector lamp, of which the most popular is MR16. MR lamps surround a halogen capsule with a computer-designed glass, or metal reflector with many surfaces or facets. These compact lamps require a glass cover, either integral or with the fixture. Typically the lamp and reflector are one unit, which directs a sharp, precise beam of light.
National Electrical Code: Sets out standards for wiring and electrical devices. The NEC requirements are widely followed by local jurisdictions.
Neon Lamp: Low pressure arc discharge lamps that operate at high voltage. Used for decoration and signage purposes.
Network: A system of dimming controls that are wired and programmed to respond together, usually to link controls in several rooms.
Occupancy Sensor: Control device that turns lights off after the space becomes unoccupied. May be ultrasonic, infrared or other type.
Opal Glass: Milky, translucent glass produced by adding ingredients to clear glass. Used for diffusing light.
Oriental Style: Classic lighting is the popular paper lantern or shade style. Chinese and Japanese motifs may also be used to decorate table and floor lamps.
Outdoor Lighting: Any hard wired, low-voltage or solar powered lighting system that is used in an exterior space. Outdoor lighting can enhance the beauty of your home, making it safer and more secure. Outdoor lighting typically is an investment that pays off in the value it adds to a home.
Outlet Box: Also Junction Box. Enclosure that protects spliced wires and supports surface fixtures.
Over Voltage: Incandescent lamps experience shortened lamp life when operated above their rated voltage.
Parabolic Luminaire: A popular type of fluorescent fixture that has a louver composed of aluminum baffles curved in a parabolic shape. The resultant light distribution produced by this shape provides reduced glare, better light control, and is considered to have greater aesthetic appeal.
Parabolic Reflector Bulbs (PAR): An incandescent, metal halide, or compact fluorescent lamp used to redirect light from the source using a parabolic reflector. PAR lamps are available with flood or spot distributions, to control the level of light more precisely. They provide about four times the light of General Service (A) bulbs and are used in recessed and track lighting. Weatherproof casings make them suitable for outdoor spot and flood lighting fixtures.
Pavers: Pavers are luminous elements mounted in the ground of a patio or pathway. They act like lighted paving stones, marking a path. Some pavers are designed to replace individual bricks, others are imbedded in concrete.
Pendant Lights: Pendants can provide both general and task lighting. With shades or globes to avoid glare, they can be suspended from the ceiling over dinette table, kitchen counters or work areas. When used over end or night tables they free up space normally occupied by table lamps. The addition of a dimmer control allows you to alter the intensity of the light to suit your mood or time of day.
Pendant Mounted: Pendant mount on a chain, stem, cable or wire, and hang down into space. The word also refers to a style of hanging fixture with a single, central luminous element (like a cone, globe or dish), distinguished from a chandelier, which typically has several arms or luminous elements.
Photocell: Light-sensitive device used to operate fixtures according to available daylight. They are used in solar lighting and to turn outdoor or security lights on and off at dusk and dawn.
Pinhole: Recessed downlight that includes a faceplate with a small aperture used for inconspicuous accent lights.
Plenum: The space between the ceiling and the floor or roof above.
Portable Lamps: Portables, typically table or floor lamps, include a cord and plug. They are distinguished from fixtures, which are permanently fastened and electrified. Portables include table lamps, floor lamps and torchieres. Small specialty lamps, such as clip-on lights, can lights, adjustable task lights, desk and piano lights also classify as portable lamps.
Post-Top Fixtures: Outdoor fixtures used to mark the entrance to a property, define a driveway or light a garden pathway.
Power Feed: The connection point that brings electricity to track and other lighting systems. Power feed may be at the end, floating or at a wiring intersection.
Prism: Refractor of transparent glass or plastic, with three or more straight sides. Light entering one side of the prism bends and exits the other side.
Pull-Down Fixture: Recessed downlight with a retractable lamp-holder/housing (usually a round-back cylinder or bullet) that pulls down from the ceiling at angles up to 90 degrees from vertical.
Quad-Tube Lamp: Single-ended compact fluorescent lamp consisting of two twin tubes on a single base.
Quartz Lamp: Or quartz halogen. Term derives from the quartz glass that encloses the filament and halogen gas. Quartz glass can withstand the high pressure of the halogen lamp, but it transmits more UV radiation than ordinary hard glass. Touching the quartz glass with bare hands leaves an oily residue that greatly reduces lamp life.
Posted in Boston Magazine, Go Green, Lighting News, Lucia Press