illuminance

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illuminance

Quotient of the luminous flux, F, incident on an element of surface divided by the area, A, of that element of surface. Symbol: E. Thus
E = F/A
The units are in lux or footcandles. Syn. illumination. See inverse square law of illumination; photometer.
References in periodicals archive ?
They reported large variations in preferred desktop illuminances, between 83 and 725 lx.
Computer simulation techniques were used in the present study to predict the average day light factor and illuminance over the work plane in office spaces for the purpose of investigating the effect of external shading devices on day lighting.
The isofootcandle plots graphically represent the luminaire's lighting pattern, in illuminance, striking a horizontal surface.
TM-24-13 concludes that both spectrum and illuminance affect vision when the visual task is based on the ability to discern detail to ensure speed and/or accuracy.
Section 2 Methods describes the luminaire under consideration, then it shows that analytical calculations based on far-field intensities are inadequate to obtain correct illuminances in the surgical site and finally it also explains how ray files were obtained by a near-field goniometer and used in simulation software to obtain illuminances.
To get the overall daylight performance metrics from work plane point illuminances, two methods are compared: (i) use the average daylight metrics of all points at each time step; (ii) at each time step, all points must meet the illuminance requirement to get one credit for that time step.
Figure 8 shows mean ratings at the four different illuminances in experiment 1 from Boyce and Cuttle; these ratings are averaged across the four levels of CCT.
The cart was then moved to the seating position of an occupant, where two illuminance measurements were made: desktop illuminance and cubic illuminance at seated head position (not reported here).
When the sensor readings were closely examined, it was found that some of the sensors measured much higher or lower illuminances than the others, sometimes higher than the outdoor illuminance.
The results have indicated the minimum, average and maximum illuminance and daylight factor in the high-rise residential building affected by building shading effect, whereas, 30m of building separation is the best distance between buildings in terms of planning to obtain the acceptable daylight and to enhance the daylight performance in the building.
Experimental results show that the solar cell is good enough for detecting the downlink signal satisfying the FEC limit even at extremely low illuminance of 100 lux.
illuminance uniformity, luminance distributions, light colour characteristics and glare.