ISO 7693:1984

Ferrotungsten — Determination of tungsten content — Cinchonine gravimetric method

The method is applicable to ferrotungsten having tungsten contents between 70 and 90 % (m/m). Specifies principle, reagents, apparatus, sample, procedure, expression of results and test report. It also specifies, in the annex, a spectrometric method for the determination of molybdenum which interferes with the determination.