This standard applies to the determination of manganese content in ferrotungsten. The determination range is less than 0.50%.
GB/T 7731.2-1987 history
2008GB/T 7731.12-2008 Ferrotungsten. Determination of sulfur content. Infrared absorption method and combustion titration method
2007GB/T 7731.2-2007 Ferrotungsten-Determination of manganese content-The periodate spectrophotometric method and the flame atomic absorption spectrometric method
1987GB/T 7731.2-1987 Methods for chemical analysis of ferrotungsten--The sodium periodate photometric method for the determination of manganese content