This standard is applicable to the determination of iron content in tungsten powder, tungsten bar, tungsten trioxide, tungstic acid and ammonium paratungstate. Measuring range: 0.0005 ~ 0.10%.
GB/T 4324.6-1984 history
2012GB/T 4324.6-2012 Methods for chemical analysis of tungsten.Part 6:Determination of iron content.1,10-phenanthroline spectrophotometry
1984GB/T 4324.6-1984 Methods for chemical analysis of tungsten--The ortho-phenanthroline photometric method for the determination of iron content