关键词: 正压检漏；介质选型；降低成本；周期时间；汽车空调系统

Abstract: With the continuous development of production technology, the vehicle manufacturing industry has put forward higher requirements for the test means of air conditioning system, and the positive pressure leak test has been applied in more and more vehicle enterprises, but the leak test media are diverse, and there is no unified reference standard for the selection of leak test media. This paper takes helium, nitrogen and compressed air, three leak test media mainly used by automobile enterprises, as the research object, through the analysis method combining theory and practice, aims to improve the efficiency of the selection of positive pressure leak test media in the air-conditioning system of each vehicle enterprise, and reduce the production cost. In this paper, from comprehensive comparative analysis of five aspects, such as the principle of positive pressure leak test, the application of positive pressure leak test media, test specifications, test equipment capacity and leak test cost, finds out the advantages and disadvantages of different leak test technology, to provide reference for the medium selection of vehicles and enterprises and derives optimal conclusions.

Key words: Positive pressure leak test; Medium selection; Reducing cost; Cycle time; Air conditioning system