GB/T 12690.15-2018 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides―Part 15: Determination of calcium content
2018GB/T 12690.15-2018 Chemical analysis methods for non-rare earth impurities of rare earth metals and their oxides―Part 15: Determination of calcium content
2006GB/T 12690.15-2006 Chemical analysis methods for non-rare earth metals and their oxide.Determination of calcium oxide content
2000GB/T 12690.28-2000 Rare earth metals and their oxide-Determination of calcium oxide content-Inductively coupled plasma atomic emission spectrographic method
1990GB/T 12690.16-1990 Rare-earth metals and their oxides--Determination of calcium content--Flame atomic absorption spectrometric method