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(General Physics) the luminous flux incident on unit area of a surface. It is measured in lux. Symbol: Ev Sometimes called: illumination Compare irradiance


(ɪˌlu məˈneɪ ʃən)

1. an act or instance of illuminating.
2. the state of being illuminated.
3. a decoration of lights.
4. Sometimes, illuminations. a display using lights as a major decoration.
5. intellectual or spiritual enlightenment.
6. the intensity of light falling at a given place on a lighted surface; the luminous flux incident per unit area, expressed in lumens per unit of area.
7. a supply of light.
8. decoration of a manuscript or book with a painted design in color and gold or silver.
9. a design used in such decoration.
[1300–50; Middle English < Latin]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.illuminance - the luminous flux incident on a unit area
brightness level, luminance, luminosity, luminousness, brightness, light - the quality of being luminous; emitting or reflecting light; "its luminosity is measured relative to that of our sun"
References in periodicals archive ?
Calculation must include the types and numbers of lamps, luminaire spacing, the value of the average maintained illuminance, uniformity of illuminance and the maintenance factor according to Annex no.
For example, if the client wants staff to see fine spatial detail, high photopic illuminance levels are needed on the task to process the visual information quickly and accurately.
Ei is the illuminance due to daylight at a point on the indoors working plane
With the new RTR-574-H, the T&D Corporation, Japanese market leader for data loggers, presents a wireless data logger that can monitor illuminance, ultraviolet light (UV), temperature and humidity.
There are four major parts in the daylighting calculation: 1) simulating the amount of direct, sky diffuse, and ground diffuse illuminance on the windows, 2) simulating the light transmitted through complex fenestration (including controls), 3) simulating the interior light inter-reflection process to obtain interior illuminance distributions and daylight metrics, and 4) simulating glare from daylight using appropriate indices.
The CL-500A Illuminance Spectrophotometer is the company's latest product offering.
A light meter was used to measure the illuminance (in lux) of each device; the light meter was cradled in a holder (made in house) while characterizing the samples.
They converted the aerial photographs into maps of lamp locations and surface illuminance.
of scenes: 12 Lighting: Peripheral lighting, task illuminance Dependent variables: Affective state Loe, Mansfield, Luminance within 40[degrees] Space: and Rowlands horizontal band about the line Conference room (1994) of sight was most important in determining the perception of brightness.
Illuminance levels of the office rooms were measured when the luminaires were at full power.
The updated specification will not affect this current white illuminance measurement.