The air purifier is a precision equipment, and the production and processing of the core purification filter screen need to pass strict quality control. Preta has a product inspection room in line with national standards, which can batch and sample test whether all links of air purifier products meet the standards, timely find and eliminate unqualified products, simulate the use effect and problems of air purifier filter screen in various environments, and adjust it in time to ensure that the produced air purifier achieves the best effect. Preta strictly implements the ISO quality management system, always implements quality control in the whole process of product production, and each refinement point is controlled by QC to ensure the high quality of each ex factory product.