Today, when I clean up my desk, I found a piece of paper whose title is Display Quality Assurance Report for LG monitor.
It looks like LG will calibrates this type of product before the factory release.
I do not understand it right now. But, I post it here for future use, since I will destroy the paper.
Gamma is the name of a nonlinear operation used to code and decode luminance in video / image. If the gamma curve of a monitor is close to the standard curve (2.2) then it means that it can reproduce brightness & contrast correctly.
Color Temperature Variation
Color temperature is a characteristic of visible light. Digital Cameras, web graphics are usually designed for a 6500K color temperature, and specification of ±500K means that there is very low tonal shift over gray scale. It means that this product can reproduce the original color tone from other devices correctly.
Color Difference: △E
△E represents the uniform difference of two colors over gray scale. If the value is under 5, it is hard to figure out the difference of the tested color and standard color, which means this product reproduces color correctly.