 |
| Fluorescent |
| A
luminescent which may or may not persist (be seen)
after removal of the excitation (most commonly a
glass tube electric lamp) is taken away. |
|
|
| Footcandle |
A
unit of illumination equal to that on a square foot
of surface that is everywhere 1 foot
from a uniform 1-candle point source, being equal
to 1 lumen/ft squared. |
|
|
| Incandescent |
| Light
given off when a metal filament is heated to a high
temperature by an electric current. |
|
|
| Lumen/Luminance
|
A
unit of light measurement, the amount of visible
light that comes to the eye from a surface.
In the special case of Dark Adaptation of the Eye,
luminances of less than about 0.034 cd/m squared
are the lowest measured light level detectable to
the human eye.
(cd/m squared means: Candela per square meter.) |
|
|
| Phosphorescent |
| A
luminescent coating used in glass tubes and lamps. |
|
|
| Photoluminescent |
Photo
– Having to do with light.
Luminescent – light given off, visible
to the eye, which had been absorbed.
Photoluminescent particles have the ability to absorb
(charge up, activate & energize) after being
excited and stimulated by light. After the light
is taken away, as in a blackout, or power failure,
the photoluminescent particles continue to emit
light. |
|
|
| Reflective |
| Light
bounced back from a surface. |
|
|
| Retroreflective |
| Light
bounced back to its source. |
|
|
| |
