This standard specifies the method for the determination of calcium content in rare earth metals and their oxides. This standard applies to the determination of calcium content in rare earth metals and their oxides. Measuring range: 0.0005% to 0.010%.
GB/T 12690.17-1990 history
2011GB/T 12690.17-2010 Chemical analysis methods of non-rare earth impurities in rare earth metals and the oxides.Part 17: Determination of niobium and tantalum contents of rare earth metals
1990GB/T 12690.17-1990 Rare-earth metals and their oxides--Determination of calcium content--Nitrous oxide-acetylene flame atomic absorption spectrometric method