In the process of ultraviolet irradiation, the penetrating force of solid substances may be relatively weak. For example, some visible light can penetrate objects, ultraviolet light cannot penetrate, such as glass, paste window paper, PVC film, dust, wall, etc. They can prevent the penetration of ultraviolet light, and cannot achieve the effect of sterilization.
The permeability of ultraviolet radiation to the environment is also poor. It can be affected by dust particles and humidity. Air containing dust particles, ultraviolet sterilization lamp efficiency will be reduced; Relative humidity increases, sterilization effect will be relatively lower. In addition, the penetration of ultraviolet light in liquid can be reduced with the increase of liquid depth. Impurities in water have a greater impact on the penetration. Dissolved salts, sugars and various organic compounds can reduce the penetration of ultraviolet light.