Card Set Information
subjective sensation that occurs in conciousness of a human behavior
objective measurement of intensity per unit of projected area
Luminaire (lighting fixture)
emits light downward, upward, or multidirectional and concentrated or diffuse
is a bright light which can interfere with visual perception
a distribution of light that is dispersed in a wide pattern and not incident from any particular direction
light emitted in a downward and upward direction, with little or no light emitted at angles near the horizontal
measured up from the nadir (straight down 0 degree angle), the angle of the first line of sight at which the care light source is not visible
a recessed surface mounted, or pendant-mounted luminaire which emits light in a downward direction with no upward component
an upward distribution of light which produces illumination on the horizontal workplane via reflection from the ceiling and upper walls
from luminaires located close to a surface being lighted, strengthens highlight and shadows
What is grazing light used for?
inspection to detect surface blemishes and errors in workmanship
What is grazing light appropriate for?
lighting heavily textured surfaces such as rough plaster, masonry, or concrete; disastrous for flat walls of smooth plaster or gypsum board
Visual Comfort Probability
rating is defined as the percentage of people who, if seated in the least desirable location in an office work space, will find a lighting installation comfortable.
excessive uncontrolled luminance reflected from objecs or surfaces in the field of view
Two additional lighting problems that cause concern for VDT users:
1) proper lighting for the non-VDT tasks the worker must also perform
2) lighting of the area in the worker's field of view