On April 16, 2007, the State Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) Circular No. 260 on Approval of 138 National Secondary Standard Substances, such as "Carbon Structural Steel Component Analysis Standard Substances", approved and issued 56 National Standard Substances developed by Jinan Zhongbiao Science and Technology Co., Ltd. The license numbers for manufacturing measuring instruments are "National Standard Substances 10000790 and 10000798".
