from The American Heritage® Dictionary of the English Language, 4th Edition
- n. See illumination.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The luminous flux incident on unit area of a surface; measured in lux or lumens
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the luminous flux incident on a unit area
Sorry, no etymologies found.
Initially, the oil was used as a lubricant for the railroad industry and as an illuminance.
A consequence of the putting into practice of so great an illuminance is that the luminance in the range of vision can no more be an optimal one, if no coloured surfaces are used in the working room.
Illumination or illuminance in various systems of units lx ph fc
The illuminance of special lighting may be up to 100% of the general lightings illuminance.
In average it will be 1 - 3% of the general lightings illuminance.
Its mean illuminance will be less than that of the general lighting.
The illuminance required in a room or at a working place must be realized - according to the respective visual task - by a suitable number and type of lamps and lighting fittings and their arrangement.
It is also possible to proceed this way: Calculation from a given arrangement of illuminators and the given luminous flux per illuminator taking into consideration the light distribution of the illuminators the illuminance, for instance at a certain point of the working area.
With the illuminance given the light source can be found.
Since the rated luminous flux is greater than the calculated one, it derives for the illuminance in point P: for high-pressure mercury vapour illumination 128 lx and for high-pressure sodium vapour illumination 139 lx