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General Electric
Industria: 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.
A light source with a built-in reflecting surface. Sometimes, the term is used to refer specifically to blown bulbs like the R and ER lamps; at other times, it includes all reflectorized lamps like PAR and MR.
Industry:Lights & lighting
A shape factor (for a room, etc.) used in lighting calculations. RCR = 5H (L+W) / L x W, or, alternately; RCR = (2.5) Total Wall Area / Floor Area; Where H = height, L = length and W = width of the room; A cubical room will have an RCR of 10; the flatter the room the lower the RCR.
Industry:Lights & lighting
Vision where the rods of the retina are exclusively responsible for seeing, typically like the light levels in the countryside on a moonless, starlit night (See also PHOTOPIC, FOVEA, FOVEAL VISION MESOPIC).
Industry:Lights & lighting
This measurement accounts for the fact that of the two light sensors in the retina, rods are more sensitive to blue light (scotopic vision) and cones to yellow light (photopic vision). The scotopic/photopic (S/P) ratio is an attempt to capture the relative strengths of these two responses. S/P is calculated as the ration of scotopic lumens to photopic lumens for the light source on an ANSI reference ballast. Cooler sources (higher colour temperatures lamps) tend to have higher values of the S/P ratio compared to warm sources.
Industry:Lights & lighting
The maximum operating temperature of the seal of the lamp in Celsius.
Industry:Lights & lighting
A discharge lamp with an integral ballasting device allowing the lamp to be directly connected to a socket providing line voltage (See CFL).
Industry:Lights & lighting
Refers to ballasts that employ a single current path passing through all lamps operated by the ballast. If one lamp should fail, companion lamps operated by the same ballasts will also extinguish or dim.
Industry:Lights & lighting
For Projection lamps, this is defined as the dimensions of the rectangular area, centred on the lamp axis, within which all luminous parts of the filament lie, when viewed perpendicular to the axis of the filament coil or to the plane of C-13 and C-13D filaments.
Industry:Lights & lighting
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.
Industry:Lights & lighting
Energy-efficient, all-purpose, tri-phosphor fluorescent lamp colours that provide good colour rendering. The CRI for SP colours is 70 or above and varies by specific lamp type.
Industry:Lights & lighting