What is the GBW standard substance certificate for VOC standard gases?

Customers who purchase VOC standard gases often request that VOC standard gases come with a national standard substance certificate, which is divided into a first level certificate and a second level certificate. The first level certificate is generally issued by the China Institute of Metrology, which is the most authoritative standard in China, while the second level certificate is applied by enterprises with certain production and analysis capabilities to the Institute of Metrology, assessed by the China Institute of Metrology, and then issued to the enterprise as a level recognition certificate after testing. 

For standard substances with different components and concentrations, the metrology institute will issue a corresponding GBW (E) certificate number. Moreover, if it is only a change in the uncertainty of the standard substance, the certificate also needs to be re audited. At present, Liquid Air China has a total of 113 standard substance certificates, covering standard substances used in various industries such as automobiles, environmental protection, petrochemicals, food, and testing. The VOC standard gases produced by the liquid air factory are accompanied by the following standard substance certificates, which will indicate the corresponding secondary standard certificate number. The relevant certificate records can be queried by entering the number in the national standard substance resource platform. Wuhan ISOTOPE Technology Co., Ltd. Service hotline: 19526388246