We often see a grey sky in the morning. In fact, it is covered by something called haze. Many people probably don't know what haze is. Its main components are formed by sulfur dioxide, nitrogen oxides and inhalable particles. The former two are gaseous pollutants, and they combine with the fog, making the sky suddenly turn grey. In fact, fog is a harmless natural phenomenon. While haze forms mainly due to the presence of a large amount of suspended particles in the air and the interaction of meteorological conditions. Haze often occurs together, and all the conditions for haze to appear simultaneously, such as moisture, calm wind, inversion, condensation nuclei, etc., are indispensable. 

The toxic components in smog not only seriously endanger people's health, but also have a significant impact on the operation of outdoor LED displays. In fact, we can classify smog into fog and haze, because the main hazards they pose to the displays are different: 

First: The harm of fog to outdoor displays 

Fog is formed by the condensation of water vapor in the air. That is to say, when the humidity in the air is high, it will cause the LED display screen to get damp. If the humidity is too high, the PCB board, power supply, power lines and other components of the display screen are prone to oxidation and corrosion, and even short circuits may occur, thereby causing malfunctions. 

Second: The harm of smog to outdoor displays 

Haze is a collection of dust, various tiny particles and other substances suspended in the air. Among them, the dust particles suspended in the air are the core component of haze. If one is exposed to haze for a long time, various fine dust in the air will enter the equipment through ventilation holes. This will accelerate the wear and even damage of fans and other equipment. The dust will also fall on the control components of the display screen, which not only reduces the heat dissipation and insulation performance of the display screen, but also accelerates the aging of the display screen and affects its normal service life. 

So, how can the display screen withstand the test in smoggy weather for a long time? This requires users and engineers to pay more attention during the procurement and maintenance processes: 

1. Firstly, during the purchasing process, users must check whether the display screen meets the dust-proof level required by the usage environment. In terms of dust-proofing, the international standard is IP0X-IP6X, which is a design level for preventing foreign objects from entering. If it is installed in the northern region with frequent sand and haze weather, both the front and back protection levels must reach IP65. That is to say, it must adopt a completely dust-proof structure, meaning it must be airtight even when sprayed with water. 

2. You must pay attention to whether the PCB board of the LED display has undergone anti-corrosion treatment, such as being coated with anti-corrosion paint on the surface; whether the power supply and power cord are of high-quality components; and whether the welding points of the screen that are prone to corrosion have undergone rust prevention treatment. 

3. During daily maintenance, it is essential to perform regular dust removal to prevent moisture absorption by dust from the air, which could lead to short circuits and cause mold growth on the PCB board and electronic components.