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 Beijing Zhonghuan environmental quality monitoring center professional third party environmental monitoring and testing agency
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Current position: illuminance
illumination
Date of issue: 2014-3-26 14:34:18 source: our website editor:

Light intensity refers to the amount of visible light received per unit area energy , abbreviated as illumination , unit Lux (Lux). A physical term used to indicate the intensity of light and the surface area of an object being illuminated degree The amount of. In photometry, "luminosity" is the density of luminous intensity in a given direction, but it is often misunderstood as illumination. The international unit of illumination is the candela received per square meter.

A quilt light On a irradiated surface illumination (illumination / illuminance) is defined as the radiation on the unit area Luminous flux Let the luminous flux on the bin DS be d Φ Then the illuminance E on this bin is: e = D Φ /dS?。 1lx=1lm/㎡。 An object uniformly illuminated by light, over an area of 1 square meter Luminous flux It's 1 Liuming Its illumination is 1 lux. Liuming yes Luminous flux Unit.

The luminous intensity is 1 candle Point source , in the unit Solid angle (1 Sphericity )Internal Luminous flux It is "1" Liuming ”。 Candela, transliteration“ Candela ”。 The concept of candlelight was first invented by British people. It is a unit of luminous intensity. At that time, the British used a pound of wax to make a foot long candle, which was defined as the light emitted by the candle. Now the definition has changed: when heated by one cubic centimeter of black light emitting body until it will melt into a liquid, 1 / 60 of the amount of light emitted is the standard light source, and the candle light is the unit of light emitted by this standard light source.

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