【摘要】 在光电效应法测普朗克常量的实验中，用３阶逐差确定光电管对各种单色光的伏安特性曲线的抬头点，可以精确到０．０１Ｖ，比作图法或其他方法精确．以此抬头点电压的绝对值作为光电管阴极材料对各种单色光的截止电压，则截止电压对于光照频率的相关因数高达０．９９９９以上，截止电压对于光照频率的线性关系的斜率以及由此斜率算出的普朗克常量，偶然误差仅为１％．可见，高阶逐差是一些物理实验中数据处理的较好方法．更多还原

【Abstract】 In the experiments of measuring Plank constant by the method of photoelectric effect, the raising point of the volt-ampere character curve of a photoelectric tube to each kind of monocromatic lights can be extracted by 3-ranking step-differential, precisely to 0.01 volt, and more precisely than by charting or other methods. The absolute value of this voltage of the raising point is considered as the cut-off voltage of the material of the negative pole of the photoelectric tube, and as the result of that, the relative factor of the cut-off voltage to the illuminated frequency is as high as 0.9999 or more, and the slope of the linear relation of the cut-off voltage to the illuminated frequeney and the Plank constant calculated with it are precise. Their accidental errors are as low as 1%, Thus, high-ranking step-differential is quite a good method in the data treatment of some physical experiments.更多还原