Luminous flux：Quantity is the sum of visible light from light source per second.unit:lumen（lm）


Photosynthetic efficiency:The luminous flux from lamps and lanterns is divided by the power of lamps and lanterns.It is one of the important indicators to measure light source energy conservation.unit:Lumens per watt（lm/w）


The efficiency of lamps and lanterns(Light transmittance):Lamps and lanterns of the ratio of flux and the bare lamp flux.


Color rendering index:For the present the object,Is the degree of vivid colors.Commonly known as "show index".unit:Ra


Color temperature:The color of the light source emits light radiation under a certain temperature light color at the same time,The temperature of the blackbody referred to as the light source color temperature.unit:kelvin（K）


Glare:View with high brightness of objects or strong brightness contrast,The visual discomfort caused by the known as glare,Dazzling light is important factor affecting the quality of lighting.


Light intensity:Light source in a certain direction within the solid Angle of luminous flux in size.unit:candela（cd）


mcd：The space of luminous flux density,The luminous flux per unit solid Angle.The preceding“m”Is pref,Is the meaning of one over one thousand(Is the meaning of one over one thousand(As the length of the unitArticle name is "m",The symbol for "m",Add a "m" in front"mm"),Chinese law so the MCD "to" milli candela".


Intensity of illumination:Is the ratio of the luminous flux and exchanges.unit:（Lux）


Brightness (intensity):Refers to the surface in the specified direction of luminous intensity and vertical and specify the direction of the light emitting area ratio of the below.unit:Candela per square meter（cd/㎡）


Light Angle:Refers to the vertical beam is one of the center line of the plane,Luminosity is equal to 50% of the second largest photometric direction Angle.


The consistency of color tolerance (color):Refers to the measured value of the color coordinates deviated from the target distance.Light color coordinates shall not deviate from the prescribed in the IEC rating 5 SDCM (x, y).That is to say,Light color coordinates should be within the prescribed ellipse.