2015DL/T 425-2015 Test method for sodium hydroxide for industrial use in fossil-flred power plant
1991DL 425.3-1991 Determination of sodium chloride content in industrial sodium hydroxide - Mercurimetry
DL 425.3-1991 Determination of sodium chloride content in industrial sodium hydroxide - Mercurimetry was changed to DL/T 425-2015 Test method for sodium hydroxide for industrial use in fossil-flred power plant.