The International Organization for Standardization (ISO) is the world's largest non-governmental standardization specialized agency and a very important organization in the field of international standardization. ISO's mission is to promote standardization and related activities on a global scale, in order to facilitate the international exchange of products and services, and to develop international mutual cooperation in knowledge, science, technology and economic activities. Among them, ISO/TC34 Food products (food), ISO/TC122 Packaging (packaging) and ISO/TC52 Light gauge metal containers (thin-walled metal containers) three standardization technical committees include international standards related to canned food quality inspection and packaging. Relevant standards are: 1SO/TR11761:1992 "Classification of can size for round cans with top openings in thin-walled metal containers according to the structure type", ISO/TR11762:1992 "Top-opening round cans for thin-walled metal containers with vaporized liquid products according to the structure Classification of can size by type" ISO/TR11776:1992 "Canned food with limited standard capacity of non-circular open cans in thin-walled metal containers" IsO1842:1991 "Determination of pH value of fruit and vegetable products", etc.