INFICON AST-ID Automotive Refrigerant IdentifierINFICON AST ID Automotive Refrigerant Identifier JAST ID AST ID is designed to verify that the refrigerant in a vehicle or cylinder meets the purity standard necessary for use or reuse. AST ID also reveals the presence of contaminants like hydrocarbons and oxygen, both of which can negatively impact the performance of an AC system. Protect your refrigerant supply from potential contamination and optimize AC performance with the accurate, easy to use