On February 7th and 8th, 2018, Shanghai Haiyingnuo Precision Instrument Co., Ltd. used a carbon black content tester DH-900B (using direct combustion method) and a thermogravimetric analyzer TGA-1000C (thermogravimetric method) to test the carbon black content data of a sample sent by a company in Jiangsu. The data met the customer's data requirements. The data measured by the two devices are as follows:

DH-900B ：3.1845% ，3.1868%. TGA-1000C: 3.04%,3.06%,3.16%.