基于CE318自动跟踪太阳光度计水汽通道（936nm）和一个窗区通道（870nm）的北京上空太阳直射辐射观测数据，利用修改的兰勒方法对大气柱水汽含量的估算方法，开展了太阳光度计的标定和北京上空水汽含量的计算等。利用探空观测结果对太阳光度计测量水汽量的标定显示，二者的线性相关性为0．986，定标不确定度为0．024g／cm^2。利用该方法对从2002至2004年观测的北京地区水汽含量进行了估算，结果表明在1，2，3，11，12月份，北京地区大气柱的水汽含量基本上小于0．5g／cm^2，三年中同月份水汽含量的平均值有较好的一致性。

Based on measurements on 936nm water-vapor band and 870nm atmospheric window band for\nCE318 sun photometer, Amethod ofwater vapor amount estmi ation by an mi proved Langley plot is presented.\nCalibration ofCE318 sun photometer and calculation ofwater vapor amount are also described. The results of\ncalibration of thewater vapor exhibited that its linear relativity is 0·986 and the uncertainty is 0·024g/cm2.\nThe results of thewater vapor amounts in 2002—2004 indicated that they are all less than 0·5g/cm2from Jan.\n(Nov. ) toMar. (Dec. ) overBeijing atmosphere. An agreement is occurred tomonthly average values ofwater\nvapor amounts yearby year.