In China, according to the standard adaptation field and effective range, it is divided into three levels : national standard, ministry standard ( professional standard ) and enterprise standard.
( 1 ) National standards The national standards are formulated by the organizations recognized by the national standardization agencies, and approved and issued by the national standardization agencies. Unified implementation of standards throughout the country. Mainly includes : basic raw materials, material standards ; industrial and agricultural product standards ; safety, health and environmental standards ; basic standards related to mutual cooperation and general technical language ; general parts, components, components, devices, accessories and tools, gauge standard ; general test and inspection method standard ; international standards that are adopted and equivalently adopted. The code of the national standard is ' GB ' ( that is, the first letter of the national standard two-character Chinese pinyin, and the number is expressed by serial number plus year number. For example, GB / T12707-91 said : No.12707 national standard, released in 1991.
( 2 ) The ministry-issued ( professional ) standards are approved and issued by the competent ministries, commissions ( bureaus ), and unified standards within the scope of the department. It mainly includes : the main product standards in this product ; general parts, components and accessories standards in this product ; the standards of equipment, tooling, tools and special raw materials in the products of this department ; typical process standards within the scope of this part ; basic standards such as terms, symbols, rules and methods commonly used in the professional field ; the test and inspection method standard of some products in this product.
( 3 ) Enterprise standards are approved and issued by enterprises ( institutions ) or their superiors. The main contents include : there is no national standard and department ( professional ) standard product standard ; in order to improve product quality, enterprises formulate product standards with performance indicators higher than national standards and departmental standards. Purchase or selection of raw materials standards ; purchase or selection and self-made tools, measuring tools, standards, etc. In principle, enterprise standards are formulated by the enterprise itself and approved by the person in charge of the enterprise. However, as the product standard of commodity delivery conditions, it needs to be approved by the superior competent unit. Once the standard is issued, it is a technical regulation. All levels of production, construction, scientific research, design management departments and enterprises, institutions, must be strictly implemented, any unit shall not change or lower the standard.
