- 行业: Energy
- Number of terms: 8202
- Number of blossaries: 3
- Company Profile:
American conglomerate currently ranked by Forbes as the world's largest company. GE has multifarious business interests including power generation and financial services.
The product of all factors that contribute to lowering the illumination level including reflector degradation, dirt, lamp depreciation over time, voltage fluctuations, etc.
Industry:Lights & lighting
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.
Industry:Lights & lighting
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.
Industry:Lights & lighting
For Stage & Studio 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.
Industry:Lights & lighting
A measure of how well a lamp maintains its light output over time. It may be expressed numerically or as a graph of light output vs. time.
Industry:Lights & lighting
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.
Industry:Lights & lighting
A ratio expressing the luminous efficacy of a light source. Typical lamp efficacies: Thomas Edison's first lamp - 1.4 lpW; Incandescent lamps - 10-40; Halogen incandescent lamps - 20-45; Fluorescent lamps - 35-105; Mercury lamps - 50-60; Metal halide lamps - 60-120; High-pressure sodium lamps - 60-140; (Note: The values above for discharge lamps do not include the effect of the ballasts, which must be used with those lamps. Taking ballast losses into account reduces "system" or lamp-ballast efficacies typically by 10-20% depending upon the type of ballast used.)
Industry:Lights & lighting
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.
Industry:Lights & lighting
