(1) Luminous flux: It is the total radiated power in watts, called radiant flux. This power must be factored by the sensitivity of the human eye to determine luminous flux in lumens.
The luminous flux is signaled as Lm. It usually measures what the amount of lighting source emits per second.

(2) Luminous intensity: Luminous intensity is an expression of the amount of light power emanating from a point source.

(3) Illumination: It is signaled by lux, measuring how much the light reflects on the surface of the item. Lux or lm/㎡ is used to express the illumination.

(4) Brightness: The effect or sensation by means of which an observer is able to distinguish differences in luminance. cd/㎡measures what amount the human eyes could see.

(5) Color temperature: Color temperature is a simple way to characterize the spectral properties of a light source. Standard unit for color temperature is Kelvin (K). Low color temperature implies warmer (more yellow/red) light while high color temperature implies a colder (more blue) light. Daylight has a rather low color temperature nearly to dawn. Below 3300K, the color looks rather red; but beyond 5300K, the color seems rather blue. The illuminating sources with the color temperature of higher than 4000K are widely adopted in tropical area, while the color temperature below 4000K in low-temperature area is common.

(6)Ra：The general color rendering index (Ra) measures the ability to show what the thing is reflected in terms of brightness. The standard is set as 100 and its values are all beneath the level 100. More Ra means more natural color people can view.

(7) optical efficiency：It measures the lighting source’s ability to transform electricity to the visible light. Alternately, it measures what the lighting source performs when consuming per watt. The higher η is, the more optical efficiency is. Optical efficiency is expressed by Lm/W.

(8)Average Life time: If a group of light is all simultaneously lighted up, how long 50% of lamps cannot functions well. H is used to measure the parameter.

(9) Lumen maintenance: The lumen will decrease as lamps work. The longer it works, the less the luminance is. Lumen maintenance in a certain time is the value that amounts to the percentage of the Lumen with the original lumen for 100 hours at fixed time.

(10)Glare：It measures how the light glares human being’s eyes, due to the disproportional distribution of light or abruptly changing light. Glare is grouped into glare and reflected glare. Strong flare could damage our eyes. What makes worse, it even causes you to be blind.

(11) Frequency-Flicker Effection：This effecting could have bad effect on the quality of work, lowering the working efficiency of those workers. However, Electronic Fluorescent Lamps do not produce flash effect thus with so-called name of “Green Lighting Engineering” product.