恒沸系的组成是分离工艺选择与化工设计的基本数据。一个大气压的标准态下常见的一些恒沸系的组成数据,有关手册作了收载,但这不敷应用,非标准态下各种恒沸系的组成均需着手实际测定。经典的测定方法是在T—X相图上描点连线,遂后顺势外延确定之。为准确起见,应配制较多的不同浓度, Constant boiling system composition is the basic choice of separation process and chemical design data. Some common data of azeotropic system under normal atmospheric pressure are included in the manual. However, this is not enough for application. The compositions of aseptic compositions under non-standard conditions need to be determined. The classic method of determination is to trace points on the T-X phase diagram connection, then determine the homeopathic extension. For the sake of accuracy, should be formulated more different concentrations,