Luminous flux
The light emitted by a light source per unit time is called the luminous
flux of the light source φ Represent, unit name: lm (lumens).
light intensity
The luminous flux emitted by a light source in a unit solid angle in a
given direction is defined as the intensity of light emitted by the
light source in that direction, represented by I.
I=luminous flux at a specific angle Ф ÷ Specific angle Ω (cd/㎡)
brightness
The luminous flux per unit solid angle per unit area of a luminous body
in a specific direction. Represented by L. L=I/S (cd/㎡), candela/m2,
also known as grayscale.
illumination
The luminous flux received per unit area, expressed as E. Lexus (Lx)
E=d Ф/ DS (Lm/m2)
E=I/R2 (R=distance from the light source to the illuminated plane)
Color temperature
When the color of the light emitted by a certain light source (thermal
radiation light source) is exactly the same as the color of the light
produced by a complete radiator (blackbody) at a certain temperature,
the temperature of the complete radiator (blackbody) is abbreviated as
color temperature (K). Color temperature is a parameter used to describe
the color of light emitted by a certain luminescent body.
Color rendering property
It refers to the influence of a certain lighting source on the color
table (the color or texture of the object itself), which is a parameter
generated by the observer consciously or unconsciously comparing it with
the color table under a reference light source (too much sunlight),
called the color rendering of the light source.
Color rendering index
A parameter used to accurately describe the color rendering of a light
source, represented by Ra. The color rendering Ra of a luminous body
(sunlight) is 100, which means that any object has the most realistic
color or texture under the illumination of sunlight.
Luminaire efficiency
The ratio of the total light flux emitted by a lamp to the total light
flux emitted by all light sources inside the lamp under the same usage
conditions, also known as the light output ratio of the lamp.
Utilization coefficient
The ratio of the total light flux received on a certain working surface
after direct and multiple reflections to the rated total light flux
emitted by a bare light source, expressed in CU.
Maintenance coefficient
The ratio of the average illuminance or brightness of a lighting device
on a specified surface after a certain period of use to the average
illuminance or brightness obtained on the same surface when the device
is newly installed under the same conditions, expressed in K.
Photoeffect
The luminous flux per unit power. symbol η, Unit name: lm/w.
Glare
A visual phenomenon that causes discomfort or reduces the ability to
observe details or targets due to inappropriate brightness distribution
or range in the field of vision, or extreme contrast. Represented by
UGR.