现行测定水质永久硬度的苏打试剂法,是在加苏打试剂前加热煮沸10分钟,以除去水中暂时硬度,然后加入苏打试剂,再煮沸5～10分钟,使相当于永久硬度的钙、镁沉淀,过滤后测定滤液中苏打试剂的余量,据以计算永久硬度。我们通过理论分析和实验验证,发现加入苏打试剂前的加热煮沸可以省掉。因为, The current determination of the water hardness of the soda reagent method is heated before adding soda reagent boiled for 10 minutes to remove the temporary hardness of water and then add soda reagent and then boiled for 5 to 10 minutes to make the equivalent of permanent hardness of calcium and magnesium precipitation, After filtration, the remaining amount of soda reagent in the filtrate was measured and the permanent hardness was calculated accordingly. Through theoretical analysis and experimental verification, we found that heating and boiling before adding soda reagent can be saved. because,