GB/T 21931.1 - 2008 uses high-frequency combustion infrared absorption method to determine the carbon content of nickel, ferronickel and nickel alloys. It clarifies the determination principle, specifies the specifications and accuracy of high-frequency combustion equipment and infrared absorption detection instruments, specifies the details of sample collection, processing and weighing, and standardizes the operation procedures of combustion process parameter setting and Gas flow rate control. The standard provides unified specifications for nickel and related alloy production, mass testing, etc., which helps to accurately determine carbon content, ensure product mass, and meet the strict requirements of different industries for the performance of nickel-based materials.