GB/T 12690.1-2022
稀土金属及其氧化物中非稀土杂质化学分析方法 第1部分:碳、硫量的测定 高频-红外吸收法
Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides—Part 1:Determination of carbon and sulfur contents—High frequency-infrared absorption method
GBT12690.1-2022, GB12690.1-2022