Maintaining good color recognition from high-pressure sodium lamps, Bullough says, can be achieved by using at least 3 footcandles
The amount of illumination is expressed in a footcandles
rating as read by the testing method described.
Its only drawback is that it cannot measure illumination below 10 footcandles
, a capacity needed when you are evaluating a facility for compliance with the Life Safety Code of the National Fire Protection Association.
The Ritter 152 Halogen Light uses a 35-watt quartz halogen bulb that provides 1,500 footcandles
at 24" for an optimum amount of quality light.
These include Irradiance in Watts, Illuminance in footcandles
and Lux, Correlated Color temperature in Kelvin, Spectral Power Distribution (SPD), and 1931 CIE xy and 1976 CIE u'v' coordinates.
The laws require light of a minimum of 10 footcandles
up to five feet from the machine, a minimum of two footcandles
from up to 50 feet from the machine, and a minimum of two footcandles
within 60 feet of a defined parking area," said Mr.
The researchers report that although the typical level of lighting in offices is 40 to 50 footcandles
, lighting in intensive care nurseries averaged 90 footcandles
in 1982 and can go as high as 190 in some -- not counting additional lighting from sunshine and sunlamps, which may add 300 footcandles
Some areas of the facility are even achieving 27 more footcandles
with LED lighting than they were with fluorescents.
Using manufacturer data, we calculated distances, beam spread and footcandles
at the distance and aiming angles.
The extremely efficient optic provides high vertical footcandles
and wider fixture spacing.
1 goal, point-in-time simulations were conducted to determine how broadly an illuminance level of 25 footcandles
[269 lux] could be achieved at 30" [0.
Illumination levels throughout the store are 75 to 80 footcandles