urs (100 x 10) or one kilowatt-hour. If the utility charges € 0.10/kWh, then the electricity cost for the 10 hours of operation would be 10 cents (1 x € 0.10)
The term used to refer to the complete light source package, including the inner parts as well a the outer bulb or tube. "Lamp", of course, is also commonly used to refer to a type of small light fixture such as a table lamp.
The lamp's identification code. For Projection lamps, this is a 3-letter-number code uniquely identifying the lamp for ordering purposes. In some instances, lamps with 3-letter (ANSI) codes are offered in more than one design voltage, in which case the voltage required should also be specified when ordering. Some GE Projection Lamps have an ordering code comprising of two or more 3-letter ANSI codes - such as EM/EKS and DYS/DYV/BHC. The first code is the ANSI code, the secondary codes identify which lamp the multiple-coded lamp can directly replace. Only the first code appears on the lamp itself. Multiple-coded lamps are so-designated by General Electric for the convenience of the customer. In nearly all cases, Miniature and Sealed Beam lamps are marked with a General Electric Trade number recorded with ANSI.
Filament lamps: Incandescent, Halogen, Halogen-IR.
Discharge Lamps: Fluorescent, HID (High Intensity Discharge)
HID Lamps: Mercury, HPS (High Pressure Sodium), MH (Metal Halide) and CMH (Ceramic Metal Halide)
(See RATED LAMP LIFE).
Radiant energy that can be sensed or seen by the human eye. Visible light is measured in lumens.
Light Center Length (L.C.L.)
The distance between the center of the filament, or arc tube, and a reference plane - usually the bottom of the lamp base. Refer to the following chart for reference plane locations.
L.C.L Reference Plane Location
|All screw bases (except Mini-Can)||Bottom of base contact|
|Mini-Can||Where diameter of ceramic base insulator is .531 inches|
|3-Contact Medium||Bottom of base contact|
|Mogul Medium Prefocus||Top of base fins|
|Mogul Prefocus||Top of base fins|
|Medium BiPost||Base end of bulb (Glass lamps)
Bottom of ceramic base (Quartz lamps)
|Mogul BiPost||Shoulder of posts (Glass lamps)
Bottom of ceramic base (Quartz lamps)
|2-Pin Prefocus||Bottom of ceramic base|
|S.C. or D.C. Bayonet Candelabra||Top of base pins|
|Medium Bayonet||Top of base pins|
|S.C. or D.C. Prefocus||Plane of locating bases on prefocus collar|
|Medium 2-Pin||Bottom of metal base shell|
Lighting Industry Federation (LIF) Code
For Showbiz/Specialty lamps, these are assigned by the Lighting Federation of London U.K. They ensure electrical and mechanical interchangeability of similarly coded lamps. LIF codes are divided into groups according to the primary application of the lamps.
(See ILLUMINANCE METER)
Light that is directed to areas where it is not needed, and thereby interferes with some visual act. Light pollution directed or reflected into the sky creates a "dome" of wasted light and makes it difficult to see stars above cities.
Light Trespass (Spill Light)
Light that is not aimed properly or shielded effectively can spill out at into areas that don't want it: it can be directed towards drivers, pedestrians or neighbors. It is distracting and annoying and can sometimes be disabling.
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.
A complete lighting unit consisting of a lamp (or lamps), ballast (or ballasts) as required together with the parts designed to distribute the light, position and protect the lamps and connect them to the power supply. A luminaire is often referred to as a fixture.
A measure of "surface brightness" when an observer is looking in the direction of the surface. It is measured in candelas per square meter (or per square foot) and was formerly referred to as "photometric brightness."
A unit of illuminance or light falling onto a surface. One lux is equal to one lumen per square meter. Ten lux approximately equals one footcandle. (See FOOTCANDLE)
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