A computer-controlled luminance meter (Konica Minolta LS-100) was used to measure the
luminous intensity of the afterglow specimens of this study.
This radiant flux value corresponds to a
luminous intensity (equal in each direction) of about 1470 Cd, compared to an average value in the area of interest of the new source of about 1000 Cd that is 68% of the original
luminous intensity.
Luminaire manufacturing tolerances and measurement uncertainties will limit the expected accuracy of the
luminous intensity data to at best a few percent when applied to production luminaires.
The
luminous intensity of monochromatic radiation in a given direction, [I.sub.v], is related to the radiant intensity of the radiation, [I.sub.e], and the spectral luminous efficacy of the radiation at the frequency of the radiation, K, by the equation [I.sub.v] = [I.sub.e] K.
The durability and flexibility of solid-state, light emitting diode (LED) light sources permits them to be readily switched on and off and adjusted in
luminous intensity through current control with no moving parts.
In fact, at the nanometric scale, the least variation in temperature,
luminous intensity, or flow of energy could cause a robot to deviate significantly from its route trying to accomplish its precise task.
The device does not require auxiliary drive circuitry, and has a
luminous intensity of 20.0 to 25.0 mcd at 5 mA.
Red, orange, yellow, and yellow-orange lamps use AlInGaP technology to produce typical
luminous intensity of 700 to 800 mcd.
For example, OSHA recommends that alarms exceed the ambient noise level by at least six decibels, and that the light intensity for visual alarms be at least 75 candelas (a measure of
luminous intensity).
Related to luminous flux is
luminous intensity. This metric, measured in candelas (cd), is the intensity of a light source in a particular direction.
Differences in
luminous intensity are assumed to affect luminous contrast -- and thus distance perception -- as shown by O'Shea, Blackburn, and Ono (1994).