The standard covers the measuring methods of sulphate of sodium hydroxide for chemical fiber use.
Test method A in the standard is applicable to sodium hydroxide products of which the sulphate content (calculating by Na2SO4) ranges between 0.001 % and 0.07 %. Test method B is applicable to products of which the sulphate content (calculating by Na2SO4) is equal to or higher than 0.01 %.
