When.com Web Search

Search results

1. Results From The WOW.Com Content Network

2. Orders of magnitude (illuminance) - Wikipedia

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

   Download QR code; Print/export ... which is a lumen per square metre. Factor Multiple Value ... Frosted incandescent light bulb [5] [6] [12] 10 6:

3. Luminous efficacy - Wikipedia

   en.wikipedia.org/wiki/Luminous_efficacy

   Luminous efficacy can be normalized by the maximum possible luminous efficacy to a dimensionless quantity called luminous efficiency.The distinction between efficacy and efficiency is not always carefully maintained in published sources, so it is not uncommon to see "efficiencies" expressed in lumens per watt, or "efficacies" expressed as a percentage.

4. Talk:Lumen (unit) - Wikipedia

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

   A standard 100 watt incandescent light bulb emits approximately 1700 lumens in North America and around 1300 lumens in 220 V areas of the world. See luminous efficacy for the specific efficiency of various types of electric light sources.

5. Luminous intensity - Wikipedia

   en.wikipedia.org/wiki/Luminous_intensity

   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 steradian then the source would have a luminous intensity of 2 candela.

6. Illuminance - Wikipedia

   en.wikipedia.org/wiki/Illuminance

   Illuminance diagram with units and terminology. In photometry, illuminance is the total luminous flux incident on a surface, per unit area. [1] It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception. [2]

7. Lumen (unit) - Wikipedia

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

   The lumen (symbol: lm) is the unit of luminous flux, a measure of the perceived power of visible light emitted by a source, in the International System of Units (SI). Luminous flux differs from power ( radiant flux ), which encompasses all electromagnetic waves emitted, including non-visible ones such as thermal radiation ( infrared ).

8. Candela - Wikipedia

   en.wikipedia.org/wiki/Candela

   The 26th General Conference on Weights and Measures (CGPM) redefined the candela in 2018. [10] [11] The new definition, which took effect on 20 May 2019, is: The candela [...] is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540 × 10 12 Hz, [a] K cd, to be 683 when expressed in the unit lm W −1, which is equal to cd sr W −1 ...

9. Luminous flux - Wikipedia

   en.wikipedia.org/wiki/Luminous_flux

   Luminous flux (in lumens) is a measure of the total amount of light a lamp puts out. 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 ...