China 'GB/T 12690.4-2021
' standard english version:
NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA
GB/T 12690.4-2021
Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides—Part 4: Determination of oxygen and nitrogen contents—Impulse-infrared absorption and impulse-thermal conductivity method 稀土金属及其氧化物中非稀土杂质化学分析方法 第4部分:氧、氮量的测定 脉冲-红外吸收法和脉冲-热导法
Issued Date:2021/10/11
Implemented Date:2022/5/1
Issued by:
The Standardization Administration of the People's Republic of China