1. Introduction Since 1998, NINGXIA LGG INSTRUMENT CO., LTD (hereafter refereed as"LONGi") had fulfilled the requirement of ISO9001 Quality Management System. In 2001, LONGI received the certificate of ISO9001 Quality Management System issued by Vouching Technical Inspection Ltd. In 2012, LONGI gained the Certificate of Measuring Management System, which was one of the earliest enterprises in the industry pass the certification. Over the years, LONGI adhere to the quality policy of "constantly meet customer requirements and continuously improve service quality", and constantly improve the management and control system. According to requirements such as GB/T19001-2008《Quality Management System Requirements》、 GB/T24001-2004 《Environmental Management System Requirements and User Manual》、 GB/T28001-2011《Occupational Health and Safety Management System》, and the actual situation of LONGI, the quality assurance & control system is established and perfected. During more than 20 years operation, quality control goes through the whole process from product design、raw-material management、production、inspection、packing、storage and after-sale service through the implementation of total quality management, which ensure the high quality service for customer.