How to discern bad when buying LED display?

Now LED display in each big mall, airport, station, are widely used in such fields as the financial industry. Large demand for the market appeared a lot of defective goods display. Spell price, cost reduction for chaos led display industry. Strong color giant as the industry leading brand, it is recommended that the customer screen of choose and buy time to look for the following six standards. 1. Flatness of the LED display surface roughness to within + / - 1 mm, to ensure that the display image is not distorted, local convex or concave leads to display the visual Angle of corner. The stand or fall of flatness is mainly decided by the production process. 2. Brightness and the viewing Angle of indoor full color brightness to above 800 CD/m2, outdoor full color brightness to above 1500 CD/m2, to guarantee the normal work of the screen, otherwise it will because the brightness is too low and can't see shown in the image. Mainly by the size of the brightness of LED tube core is good or bad decision. Viewing angles directly depends on the size of the display screen of the audience, and the bigger the better. The size of the viewing Angle is mainly composed of tube core encapsulated way to decide. 3. The white balance effect white balance effect is one of the most important indicator display. Chromatology on red, green and blue color for the proportion of 1:4. Lost. 16 will only show the pure white, if the actual rate is a little deviation will appear white balance deviation, generally pay attention to whether there is a slant blue, white slant yellow phenomenon. The stand or fall of the white balance is mainly composed of display control system to determine, tube core of color reducibility may also be affected. 4. The reducibility of color reducibility is refers to the display of color reducibility, the color of the display shows both to maintain highly consistent with the colour of the source, so as to ensure the image sense of reality. 5. Dead refers to the phenomenon of Mosaic Mosaic, appear on the screen normally on or often black small four squares, both module necrosis phenomenon, the main reason for the display of connectors quality closes nevertheless. Dead point refers to appear on the LED display normally on or black often a single point, how many of the dead point mainly determined by the stand or fall of pipe core. 6. Exist between those with and without the shades of color piece is refers to the adjacent modules are clear off color, color transition in module, color piece phenomenon caused mainly by the control system is poorer, grey level is not high, caused by lower scanning frequency.