Calculation of significant digits of dissolved oxygen in seawater by iodimetry

At present, the open of monitoring data is the important working of monitoring system.Significant digits indicate the reliability of date.Dissolved oxygen (DO) is a routine environmental monitoring item.In this paper, we discuss and calculate the significant digits of dissolved oxygen in seawater by iodimetry.The results show that the concentration of Na₂S₂O₃ and the volume of Na₂S₂O₃ and water sample are the three key influence factors.And in general, the concentration of Na₂S₂O₃ is three digits; and the volume of Na₂S₂O₃ is three or four digits; the volume water sample is five digits; the DO measure results are three digits.