The measurement range of carbonate content in caustic soda inGB769887 was studied. First the low content measuring value was conducted based on the low measuring limit of the system, then a new measurement range of GB769887 was established. This new measurement range was further confirmed by experiments. The results of this study was further confirmed by experiments. The results if this study has greatly expanded the measurement range of GB769887, at the same time provide an effective analytical method for industrial practices.
