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2. Fluorescent-lamp formats - Wikipedia

   en.wikipedia.org/wiki/Fluorescent-lamp_formats

   High-lumen retrofit lamps for 40W T12 lamps in North America. Popular tube diameter in Japan; Circular 32W and 40W T10 lamps (Older versions of the 32W and 40W T9 lamps) T12 T38 1 + 1 ⁄ 2: 38.1 G13 bi-pin; Fa8 single-pin; R17d recessed double contact; One of the first diameters of fluorescent lamps, with the 15W T12 and 20W T12 having been ...

3. Luminous flux - Wikipedia

   en.wikipedia.org/wiki/Luminous_flux

   The luminous intensity (in candelas) is a measure of how bright the beam in a particular direction is. If a lamp has a 1 lumen bulb and the optics of the lamp are set up to focus the light evenly into a 1 steradian beam, then the beam would have a luminous intensity of 1 candela. If the optics were changed to concentrate the beam into 1/2 ...

4. Luminous efficacy - Wikipedia

   en.wikipedia.org/wiki/Luminous_efficacy

   Luminous efficacy of radiation measures the fraction of electromagnetic power which is useful for lighting. It is obtained by dividing the luminous flux by the radiant flux. [4] Light wavelengths outside the visible spectrum reduce luminous efficacy, because they contribute to the radiant flux, while the luminous flux of such light is zero ...

5. Fluorescent lamp - Wikipedia

   en.wikipedia.org/wiki/Fluorescent_lamp

   Fluorescent lamp tubes are often straight and range in length from about 100 millimeters (3.9 in) for miniature lamps, to 2.43 meters (8.0 ft) for high-output lamps. Some lamps have a circular tube, used for table lamps or other places where a more compact light source is desired.

6. Orders of magnitude (illuminance) - Wikipedia

   en.wikipedia.org/wiki/Orders_of_magnitude...

   Fluorescent lamp [5] [6] 10 5: 75 kcd/m 2: Low pressure sodium-vapor lamp [6] 130 kcd/m 2: Frosted incandescent light bulb [5] [6] [12] 10 6: Mcd/m 2: 600 kcd/m 2: Solar disk at horizon [5] 10 7: 7 Mcd/m 2: Filament of a clear incandescent lamp [13] 10 8: 100 Mcd/m 2: Possible retinal damage [4] 10 9: Gcd/m 2: 1.6 Gcd/m 2: Solar disk at noon [5 ...

7. Lumen (unit) - Wikipedia

   en.wikipedia.org/wiki/Lumen_(unit)

   A 470-lumen LED lamp. It consumes about one sixth the electrical power of an incandescent light bulb producing the same light. Lamps used for lighting are commonly labelled with their light output in lumens; in many jurisdictions, this is required by law. A 23 W spiral compact fluorescent lamp emits about 1,400–1,600 lm.