GB/T 223.85 - 2009 Determination of sulfur content in steel and alloys by infrared absorption method after combustion in induction furnace. The standard specifies the determination principle, specifies the technical parameters of key equipment such as induction furnace and infrared absorption instrument, specifies the selection of samples, the preparation process and the requirements of weighing sample volume, and strictly stipulates the operation points such as heating rate and gas environment in the combustion process. With this standard, the sulfur content in steel and alloys can be accurately detected, providing a unified method for steel production and mass control, helping to improve the mass of steel products and meet the strict standards of steel material performance in various industries.