GB/T 12690.4-2003

Chemical analysis methods for non-rare earth impurities ofrare earth metals and their oxides--Determination of oxygen and nitrogen content--Impulse-infrared and impulse-thermal conductance absorption method

稀土金属及其氧化物中非稀土杂质化学分析方法 氧、氮量的测定 脉冲-红外吸收法和脉冲-热导法