Product inspection and testing

According to the different requirements of the use of products, each product has its own quality characteristics. These characteristics are generally translated into specific quality requirements in the product technical standards (national standards, industry standards, enterprise standards) and other relevant product design drawings, process and manufacturing technical documents, as the basis for quality inspection and post-inspection comparison test results of the reference base. In order to ensure the quality of products, it is necessary to conduct quality inspection on raw materials, purchased parts, outsourced parts, blank, semi-finished products, finished products and so on in the production process, and strictly control, so that unqualified raw materials are not put into production, unqualified semi-finished products are not transferred, unqualified parts are not assembled, unqualified products are not delivered, so as to ensure the interests of the country and consumers. Maintain the reputation of producers and improve social benefits. Product quality inspection is an important part of quality management in production. In the small-scale production workshop in the era of handicraft production before the Industrial Revolution, one or several production personnel completed the whole process of production, the operator self-inspection and self-responsibility. With the gradual expansion of production scale, the direct management of production authorized special personnel to complete the quality inspection work among the operators, forming the early inspection personnel. In the early 20th century, during World War I and before World War II, the American engineer F.W. Under the advocacy of Taylor, inspection was separated from the production process as a management function, and a full-time inspection system was established, including the establishment of full-time inspection personnel and inspection institutions, and the formulation of technical standards for inspection. In the 1920s, the representative of American engineer W.A. Hughart and others, aiming at the shortcomings of quality inspection merely playing the role of "post-inspection", introduced the method of mathematical statistics and proposed the concepts, principles and methods of sampling inspection and statistical process control, which were forced to be adopted by the American military in procurement during the Second World War. With the development of industrial technology, the automation degree of production process is increasing day by day, the automatic online detection technology is widely used, and the integration degree of inspection is also increasing obviously. Automatic production, automatic detection, automatic judgment, automatic feedback, automatic compensation are timely controlled and adjusted by the computer closed-loop system, so that the quality inspection level and timeliness has been greatly improved. Product quality inspection can be divided into four steps: (1) familiar with the requirements, choose the inspection method. ② Measure or test. (3) Compare and judge. (4) Record and process. Inspection personnel signature confirmation and approval. According to the inspection records and the results of the judgment, to decide whether the product (single or lot) can be received and released.